First Simultaneous K-p -> (Sigma0/ Lambda0) pi0 Cross Sections Measurements at 98 MeV/c
K. Piscicchia, M. Skurzok, M. Cargnelli, R. Del Grande, L. Fabbietti, J. Marton, P. Moskal, A. Scordo, A. Ramos, D. L. Sirghi, O. Vazquez Doce, J. Zmeskal, S. Wycech, P. Branchini, F. Ceradini, E. Czerwinski, E. De Lucia, S. Fiore, A. Kupsc, G. Mandaglio, M. Martini, A. Passeri, V. Patera, E. Perez Del Rio, A. Selce, M. Silarski and C. Curceanu
abstract
We report the first simultaneous and independent measurements of the K-p -> Sigma0 pi0 and K-p -> Lambda0 pi0 cross sections around 100 MeV/c kaon momentum. The kaon beam delivered by the DAFNE collider was exploited to detect K- absorptions on Hydrogen atoms, populating the gas mixture of the KLOE drift chamber. The precision of the measurements sigma_{K-p -> Sigma0 pi0} =42.8 +-1.5(stat:)+2.4-2.0(syst:) mb and sigma_{K-p -> Lambda0 pi0}= 31.0 +- 0.5(stat:)+1.2-1.2(syst:) mb is the highest
yet obtained in the low kaon momentum regime.
3D melanoma spheroid model for the development of positronium biomarker
H. Karimi, P. Moskal, E.Ł. Stępień
abstract
It was recently demonstrated that newly invented positronium imaging may be used for improving cancer diagnostics by providing additional information about tissue pathology with respect to the standardized uptake value currently available in positron emission tomography (PET). Positronium imaging utilizes properties of a positronium atoms, which are built from the electron and positron produced in the body during PET examinations.
We hypothesized whether positronium imaging would be sensitive to in vitro discrimination of tumour-like three-dimensional structures (spheroids) build of melanoma cell lines with different cancer activity and biological properties.
The lifetime of ortho-Positronium (o-Ps) was evaluated in melanoma spheroids from two cell lines (WM266-4 and WM115) differing in the stage of malignancy. Additionally, we considered such parameters: as cell size, proliferation rate and malignancy to evaluate their relationship with o-Ps lifetime. We demonstrate the pilot results for the o-Ps lifetime measurement in extracellular matrix free spheroids. With the statistical significance of two standard deviations, we demonstrated that the higher the degree of malignancy and the rate of proliferation of neoplastic cells the shorter the lifetime of ortho-positronium. In particular we observed following indications encouraging further research: (i) WM266-4 spheroids characterized with higher proliferation rate and malignancy showed shorter o-Ps lifetime compared to WM115 spheroids characterized by lower growth rate, (ii) Both cell lines showed a decrease in the lifetime of o-Ps after spheroid generation in 8th day comparing to 4th day in culture and the mean o-Ps lifetime is longer for spheroids formed from WM115 cells than these from WM266-4 cells, regardless spheroid age. The results of these study revealed that positronium is a promising biomarker that may be applied in PET diagnostics for the assessment of the degree of cancer malignancy.
Search for eta-mesic nuclei: A review of experimental and theoretical advances
A. Khreptak, M. Skurzok, P. Moskal
abstract
In the mid-1980s, theoreticians predicted possible exotic states of an eta meson and a nucleus bound by the strong interaction, so-called mesic nucleus. This led to extensive experimental efforts aimed at discovering such unstable states as well as understanding the underlying interactions via eta meson production reactions. As experiments yielded new data, more and more sophisticated theoretical models were developed to understand the fundamental eta-nucleon and eta-nucleus interactions. After more than 35 years of research in this field, several signals have been identified as possible indications of hypothetical eta-mesic nuclei, but there is still no general agreement or clear confirmation of their existence. In the paper, we review the study of the eta-mesic nuclei with an emphasis on recent research activities.
Extracellular vesicles in vascular pathophysiology: beyond their molecular content
E.Ł. Stępień, M. Durak-Kozica, P. Moskal
abstract
Extracellular vesicles (EVs) are released by all cells, both in physiological and pathological conditions. Their molecular charge and composition emerge as possible biomarkers, but EVs may also be considered for other clinical applications. This review discusses the role of other features of EVs, such as their lipid components or composition of glycans that form the EV corona and regulate EV biodistribution and uptake by target cells. The importance of EV electric charge has been discussed as a new insight into EV fate and destination.
Comparative studies of the sensitivities of sparse and full geometries of Total-Body PET scanners built from crystals and plastic scintillators
M. Dadgar*, S. Parzych, J. Baran, N. Chug, C. Curceanu, E. Czerwiński, K. Dulski, K. Elyan, A. Gajos, B.C. Hiesmayr, Ł. Kapłon, K. Klimaszewski, P. Konieczka, G. Korcyl, T. Kozik, W. Krzemień, D. Kumar, S. Niedźwiecki, D. Panek, E. Perez del Rio, L. Raczyński, S. Sharma, Shivani, R.Y. Shopa, M. Skurzok, E. L. Stępień, F. Tayefi Ardebili, K. Tayefi Ardebili, S. Vandenberghe, W. Wiślicki and P. Moskal
abstract
Background: Alongside the benefits of Total-Body imaging modalities, such as higher sensitivity, single-bed position, low dose imaging, etc., their final construction cost prevents worldwide utilization. The main aim of this study is to present a simulation-based comparison of the sensitivities of existing and currently developed tomographs to introduce a cost-efficient solution for
constructing a Total-Body PET scanner based on plastic scintillators.
Methods: For the case of this study, eight tomographs based on the uEXPLORER configuration with different scintillator materials (BGO, LYSO), axial field-of-view (97.4 cm and 194.8 cm), and detector configuration (full and sparse) were simulated. In addition, 8 J-PET scanners with different configurations, such as various axial field-of-view (200 cm and 250 cm), the different cross-sections of plastic scintillator, and the multiple numbers of the
plastic scintillator layers (2, 3, and 4), based on J-PET technology have been simulated by GATE software. Furthermore, Biograph Vision has been simulated to compare the results with standard PET scans. Two types of simulations have been performed. The first one with a centrally located source with a diameter of 1mm and a length of 250 cm, and the second one with the same source inside a water-filled cylindrical phantom with a diameter of 20 cm and a length of 183 cm.
Results: With regards to sensitivity, among all the proposed scanners, the ones constructed with BGO crystals give the best performance (? 350 cps/kBq at the center). The utilization of sparse geometry or LYSO crystals significantly lowers the achievable sensitivity of such systems. The J-PET design gives a similar sensitivity to the sparse LYSO crystal-based detectors while having full detector coverage over the body. Moreover, it provides uniform sensitivity over the body
with additional gain on its sides and provides the possibility for high-quality brain
imaging.
Conclusion: Taking into account not only the sensitivity but also the price of the Total-Body PET tomographs, which till now was one of the main obstacles in their widespread clinical availability, the J-PET tomography system based on plastic scintillators could be a cost-efficient alternative for Total-Body PET scanners.
Efficiency determination of J-PET: first plastic scintillators-based PET scanner
S. Sharma, J. Baran, N. Chug, C. Curceanu, E. Czerwiński, M. Dadgar, K. Dulski, K. Eliyan, A. Gajos, N. Gupta?Sharma, B. C. Hiesmayr, K. Kacprzak, Ł. Kapłon, K. Klimaszewski, P. Konieczka, G. Korcyl, T. Kozik, W. Krzemień, D. Kumar, Sz. Niedźwiecki, D. Panek, S. Parzych, E. Perez del Rio, L. Raczyński, Shivani, R. Y. Shopa, M. Skurzok, E. Ł. Stępień, F. Tayefi, K. Tayefi , W. Wiślicki and P. Moskal
abstract
Background:
The Jagiellonian Positron Emission Tomograph is the 3?layer prototype
of the first scanner based on plastic scintillators, consisting of 192 half?metre?long strips
with readouts at both ends. Compared to crystal?based detectors, plastic scintillators
are several times cheaper and could be considered as a more economical alternative to
crystal scintillators in future PETs. JPET is also a first multi?photon PET prototype. For the
development of multi?photon detection, with photon characterized by the continu?
ous energy spectrum, it is important to estimate the efficiency of J?PET as a function
of energy deposition. The aim of this work is to determine the registration efficiency
of the J?PET tomograph as a function of energy deposition by incident photons and
the intrinsic efficiency of the J?PET scanner in detecting photons of different incident
energies. In this study, 3?hit events are investigated, where 2?hits are caused by 511 keV
photons emitted in e+e? annihilations, while the third hit is caused by one of the
scattered photons. The scattered photon is used to accurately measure the scattering
angle and thus the energy deposition. Two hits by a primary and a scattered photon
are sufficient to calculate the scattering angle of a photon, while the third hit ensures
the precise labeling of the 511 keV photons.
Results:
By comparing experimental and simulated energy distribution spectra, the
registration efficiency of the J?PET scanner was determined in the energy deposition
range of 70?270 keV, where it varies between 20 and 100%. In addition, the intrinsic
efficiency of the J?PET was also determined as a function of the energy of the incident
photons.
Conclusion:
A method for determining registration efficiency as a function of energy
deposition and intrinsic efficiency as a function of incident photon energy of the J?PET
scanner was demonstrated. This study is crucial for evaluating the performance of the
scanner based on plastic scintillators and its applications as a standard and multi?pho?
ton PET systems. The method may be also used in the calibration of Compton?cameras
developed for the ion?beam therapy monitoring and simultaneous multi?radionuclide
imaging in nuclear medicine.
Developing a Novel Positronium Biomarker for Cardiac Myxoma Imaging
P. Moskal, E. Kubicz, G. Grudzień, E. Czerwiński, K. Dulski, B. Leszczyński, S. Niedźwiecki, E.Ł. Stępień
abstract
Purpose: Cardiac myxoma (CM), the most common cardiac tumor in adults, accounts for 50?75% of benign cardiac tumors. The diagnosis of CM is often elusive, especially in young stroke survivors and transthoracic echocardiography (TTE) is the initial technique for the differential diagnostics of CM. Less invasive cardiac computed tomography (CT) and magnetic resonance imaging (MRI) are not available for the majority of cardiac patients. Here, a robust imaging approach, ortho-Positronium (o-Ps) imaging, is presented to determine cardiac myxoma extracted from patients undergoing urgent cardiac surgery due to unexpected atrial masses. We aimed to assess if the o-Ps atom, produced copiously in intramolecular voids during the PET imaging, serves as a biomarker for CM diagnosing.
Methods: Six perioperative CM and normal (adipose) tissue samples from patients, with primary diagnosis confirmed by the histopathology examination, were examined using positron annihilation lifetime spectroscopy (PALS) and micro-CT. Additionally, cell cultures and confocal microscopy techniques were used to picture cell morphology and origin.
Results: We observed significant shortening in the mean o-Ps lifetime in tumor with compare to normal tissues: an average value of 1.92(02) ns and 2.72(05) ns for CM and the adipose tissue, respectively. Microscopic differences between tumor samples, confirmed in histopathology examination and micro-CT, did not influenced the major positronium imaging results.
Conclusions: Our findings, combined with o-Ps lifetime analysis, revealed the novel emerging positronium imaging marker (o-PS) for cardiovascular imaging. This method opens the new perspective to facilitate the quantitative in vivo assessment of intracardiac masses on a molecular (nanoscale) level.
Measurements of high-n transitions in intermediate mass kaonic atoms by SIDDHARTA-2 at DAFNE
F. Sgaramella, M. Tuchler, C. Amsler, M. Bazzi, D. Bosnar, A. M. Bragadireanu, M. Cargnelli, M. Carminati, A. Clozza, G. Deda, L. De Paolis, R. Del Grande, L. Fabbietti, C. Fiorini, I. Friscic, C. Guaraldo, M. Iliescu, M. Iwasaki, A. Khreptak, S. Manti, J. Marton, M. Miliucci, P. Moskal, F. Napolitano, S. Niedźwiecki, H. Onishi, K. Piscicchia, Y. Sada, A. Scordo, M. Silarski, D. Sirghi, F. Sirghi, M. Skurzok, A. Spallone, K. Toho, O. Vazquez Doce, J. Zmeskal, E. Widmann, C. Yoshida, C. Curceanu
abstract
The SIDDHARTA-2 experiment installed at the DAFNE collider of INFN-LNF performed, for the first time,
measurements of high-n transitions in intermediate mass kaonic atoms during the data taking campaigns of 2021 and
2022. Kaonic carbon, oxygen, nitrogen and aluminium transitions, which occur in the setup materials, were measured
by using the kaons stopped in the gaseous helium target cell with aluminium frames and Kaptonwalls, and are reported in
this paper. These new kaonic atoms measurements add valuable input to the kaonic atoms transitions data base, which is
used as a reference for theories and models of the low-energy strong interaction between antikaon and nuclei. Moreover,
these results pave the way for future dedicated kaonic atoms measurements through the whole periodic table and to a new
era for the antikaon-nuclei studies at low energy.
Comparative studies of plastic scintillator strips with high technical attenuation length for the total-body J-PET scanner
Ł. Kapłon, J. Baran, N. Chug, A. Coussat, C. Curceanu, E. Czerwiński, M. Dadgar, K. Dulski, J. Gajewski, A. Gajos, B. Hiesmayr, E. Kavya Valsan, K. Klimaszewski, G. Korcyl, T. Kozik, W. Krzemień, D. Kumar, G. Moskal, S. Niedźwiecki, D. Panek, S. Parzych, E. Pérez del Rio, L. Raczyński, A. Ruciński, S. Sharma, S. Shivani, R. Shopa, M. Silarski, M. Skurzok, E. Stępień, F. Tayefi Ardebili, K. Tayefi Ardebili, W. Wiślicki, P. Moskal
abstract
Plastic scintillator strips are considered as one of the promising solutions for the cost-effective construction of total-body positron emission tomography, (PET) system. The purpose of the performed measurements is to compare the transparency of long plastic scintillators with dimensions 6 mm
24 mm
1000 mm and with all surfaces polished. Six different types of commercial, general purpose, blue-emitting plastic scintillators with low attenuation of visible light were tested, namely: polyvinyl toluene-based BC-408, EJ-200, RP-408, and polystyrene-based Epic, SP32 and UPS-923A. For determination of the best type of plastic scintillator for total-body Jagiellonian positron emission tomograph (TB-J-PET) construction, emission and transmission spectra, and technical attenuation length (TAL) of blue light-emitting by the scintillators were measured and compared. The TAL values were determined with the use of UV lamp as excitation source, and photodiode as light detector. Emission spectra of investigated scintillators have maxima in the range from 420 nm to 429 nm. The BC-408 and EJ-200 have the highest transmittance values of about 90% at the maximum emission wavelength measured through a 6 mm thick scintillator strip and the highest technical attenuation length reaching about 2000 mm, allowing assembly of long detection modules for time-of-flight (TOF) J-PET scanners. Influence of the 6 mm × 6 mm, 12 mm × 6 mm, 24 mm × 6 mm cross-sections of the 1000 mm long EJ-200 plastic scintillator on the TAL and signal intensity was measured. The highest TAL value was determined for samples with 24 mm × 6 mm cross-section.
Positronium physics and biomedical applications
S.D. Bass, S. Mariazzi, P. Moskal, E. Stepien
abstract
Positronium is the simplest bound state, built of an electron and a positron. Studies of positronium in vacuum and its decays in medium tell us about Quantum Electrodynamics, QED, and about the structure of matter and biological processes of living organisms at the nanoscale, respectively. Spectroscopic measurements constrain our understanding of QED bound state theory. { Searches for rare decays and measurements of the effect of gravitation on positronium are used to look for new physics phenomena. In biological materials positronium decays} are sensitive to the inter- and intra-molecular structure and to the metabolism of living organisms ranging from single cells to human beings. This leads to new ideas of positronium imaging in medicine using the fact that during positron emission tomography (PET) as much as 40% of positron annihilation occurs through the production of positronium atoms inside the patient?s body. A new generation of the high sensitivity and multi-photon total-body PET systems opens perspectives for clinical applications of positronium as a biomarker of tissue pathology and the degree of tissue oxidation.
J-PET detection modules based on plastic scintillators for performing studies with positron and positronium beams
S. Sharma, J. Baran, R.S. Brusa, R. Caravita, N. Chug, A. Coussat, C. Curceanu, E. Czerwinski, M. Dadgar, K. Dulski, K. Eliyan, A. Gajos, B.C. Hiesmayr, K. Kacprzak, L. Kaplon, K. Klimaszewski, P. Konieczka, G. Korcyl, T. Kozik, W. Krzemien D. Kumar, S. Mariazzi, S. Niedźwiecki, L. Panasa, S. Parzych, L. Povolo, E. Perez del Rio, L. Raczynski Shivani, R.Y. Shopa, M. Skurzok, E.L. Stepien, F. Tayefi, K. Tayefi, W. Wislicki and P. Moskal
abstract
The J-PET detector, which consists of inexpensive plastic scintillators, has demonstrated its potential in the study of fundamental physics. In recent years, a prototype with 192 plastic scintillators arranged in 3 layers has been optimized for the study of positronium decays. This allows performing precision tests of discrete symmetries (C, P, T) in the decays of positronium atoms. Moreover, thanks to the possibility of measuring the polarization direction of the photon based on Compton scattering, the predicted entanglement between the linear polarization of annihilation photons in positronium decays can also be studied. Recently, a new J-PET prototype was commissioned, based on a modular design of detection units. Each module consists of 13 plastic scintillators and can be used as a stand-alone, compact and portable detection unit. In this paper, the main features of the J-PET detector, the modular prototype and their applications for possible studies with positron and positronium beams are discussed. Preliminary results of the first test experiment performed on two detection units in the continuous positron beam recently developed at the Antimatter Laboratory (AML) of Trento are also reported.
TOF MLEM Adaptation for the Total-Body J-PET with a Realistic Analytical System Response Matrix
R.Y. Shopa, J. Baran, K. Klimaszewski, W. Krzemień, L. Raczyński, W. Wiślicki, K. Brzeziński, N. Chug, A. Coussat, C. Curceanu, E. Czerwiński, M. Dadgar, K. Dulski, J. Gajewski, A. Gajos, B.C. Hiesmayr, E. Kavya Valsan, G. Korcyl, T. Kozik, D. Kumar, Ł. Kapłon, G. Moskal, S. Niedźwiecki, D. Panek, S. Parzych, E. Pérez del Rio, A. Ruciński, S. Sharma, Shivani, M. Silarski, M. Skurzok, E. Stepień, F. Tayefi Ardebili, K. Tayefi Ardebili, P. Moskal
abstract
We report a study of the original image reconstruction algorithm based on the time-of-flight maximum likelihood expectation maximisation (TOF MLEM), developed for the total-body (TB) Jagiellonian PET (J-PET) scanners. The method is applicable to generic cylindrical or modular multi-layer layouts and is extendable to multi-photon imaging. The system response matrix (SRM) is represented as a set of analytical functions, uniquely defined for each pair of plastic scintillator strips used for the detection. A realistic resolution model (RM) in detector space is derived from fitting the Monte Carlo simulated emissions and detections of annihilation photons on oblique transverse planes. Additional kernels embedded in SRM account for TOF, parallax effect and axial smearing. The algorithm was tested on datasets, simulated in GATE for the NEMA IEC and static XCAT phantoms inside a 24-module 2-layer TB J-PET. Compared to the reference TOF MLEM with none or a shift-invariant RM, an improvement was observed, as evaluated by the analysis of image quality, difference images and ground truth metrics. We also reconstructed the data with additive contributions, pre-filtered geometrically and with non-TOF scatter correction applied. Despite some deterioration, the obtained results still capitalise on the realistic RM with better edge preservation and superior ground truth metrics. The envisioned prospects of the TOF MLEM with analytical SRM include its application in multi-photon imaging and further upgrade to account for the non-collinearity, positron range and other factors.
Experience and new prospects of PET imaging for ion beam therapy monitoring
K. Parodi, T. Yamaya, P. Moskal
abstract
Pioneering investigations on the usage of positron-emission-tomography (PET) for the monitoring of ion beam therapy with light (protons, helium) and heavier (stable and radioactive neon, carbon and oxygen) ions started shortly after the first realization of planar and tomographic imaging systems, which were able to visualize the annihilation of positrons resulting from irradiation induced or implanted positron emitting nuclei. And while the first clinical experience was challenged by the utilization of instrumentation directly adapted from nuclear medicine applications, new detectors optimized for this unconventional application of PET imaging are currently entering the phase of (pre)clinical testing for more reliable monitoring of treatment delivery during irradiation. Moreover, recent advances in detector technologies and beam production open several new exciting opportunities which will not only improve the performance of PET imaging under the challenging conditions of in-beam applications in ion beam therapy, but will also likely expand its field of application. In particular, the combination of PET and Compton imaging can enable the most efficient utilization of all possible radiative emissions for both stable and radioactive ion beams, while positronium lifetime imaging may enable probing new features of the underlying tumour and normal tissue environment. Thereby, PET imaging will not only provide means for volumetric reconstruction of the delivered treatment and in-vivo verification of the beam range, but can also shed new insights for biological optimization of the treatment or treatment response assessment.
New measurements of kaonic helium-4 L-series X-rays yields in gas with the SIDDHARTINO setup
D. L. Sirghi, H. Shi, C. Guaraldo, F. Sgaramella, C. Amsler, M. Bazzi, D. Bosnar, A. M. Bragadireanu, M. Cargnelli, M. Carminati, A. Clozza, G. Deda, L. De Paolis, R. Del Grande, L. Fabbietti, C. Fiorini, M. Iliescu, M. Iwasaki, J. Marton, M.. Miliucci, P. Moskal, F. Napolitano, S. Niedźwiecki, H. Onishi, K. Piscicchia, Y. Sada, A. Scordo, M. Silarski, F. Sirghi, M. Skurzok, A. Spallone, K. Toho, M. Tüchler, O. Vazquez Doce, J. Zmeskal, C. Yoshida, C. Curceanu
abstract
The L-series X-rays transitions of the kaonic helium-4 exotic atom were measured by SIDDHARTINO,
the reduced configuration of the SIDDHARTA-2 experiment, at the DANE collider of INFN-LNF, with
gaseous 4He targets at densities of 1.90 g/l and 0.82 g/l, corresponding to 1.5% and 0.66%, respectively, of
the liquid helium-4 density. The absolute yields for the L? transition are determined to be 0.15 ?0.03 and
0.12 ?0.03, for the two target densities. The yields for the L? and L? transitions are presented relatively
to that of the L? transition. These results are compatible with the yields measured by the SIDDHARTA
experiment at the densities of 1.65 g/l and 2.15 g/l and contribute to refine the cascade models describing
the de-excitation of kaonic atoms as function of density.
? 2022 Elsevier B.V. All rights reserved.
Performance of the SABAT Neutron-Based Explosives Detector Integrated with an Unmanned Ground Vehicle: A Simulation Study
M. Silarski, M. Nowakowski
abstract
The effective and safe detection of illicit materials, explosives, in particular, is currently of growing importance taking into account the geopolitical situation and increasing risk of a terrorist attack. The commonly used methods of detection are based predominantly on metal detectors and georadars, which show only the shapes of the possible dangerous objects and do not allow for exact identification and risk assessment. A supplementary or even alternative method may be based on neutron activation analysis, which provides the possibility of a stoichiometric analysis of the suspected object and its non-invasive identification. One such sensor is developed by the SABAT collaboration, with its primary application being underwater threat detection. In this article, we present performance studies of this sensor, integrated with a mobile robot, in terms of the minimal detectable quantity of commonly used explosives in different environmental conditions. The paper describes the functionality of the used platform considering electronics, sensors, onboard computing power, and communication system to carry out the manual operation and remote control. Robotics solutions based on modularized structures allow the extension of sensors and effectors that can significantly improve the safety of personnel as well as work efficiency, productivity, and flexibility.
Feasibility study of positronium application for blood clots structural characteristics
S. Moyo, P. Moskal, E. Stępień
abstract
Positron-electron annihilation in living organisms occurs in about 30% via the formation of a metastable ortho-positronium atom that annihilates into two 511 keV photons in tissues because of the pick-off and conversion processes. Positronium (Ps) annihilation lifetime and intensities can be used to determine the size and quantity of defects in a material's microstructure, such as voids or pores in the range of nanometers. This is particularly true for blood clots. Here we present pilot investigations of positronium properties in fibrin clots. The studies are complemented by the use of SEM Edax and micro-computed tomography (microCT) to evaluate the extracted thrombotic material's properties. microCT is a versatile characterization method offering in situ and in operando possibilities and is a qualitative diagnostic tool. With microCT the presence of pores, cracks, and structural errors can be verified, and hence the 3D inner structure of samples can be investigated.
Transcriptomic data analysis of melanocytes and melanoma cell lines of LAT transporter genes for precise medicine
M. Szczepanek, D. Panek, M. Przybyło, P. Moskal, E. Stępień
abstract
Background: Boron Neutron Capture Therapy (BNCT) is a two-step treatment that can be used in some types of cancers. It involves administering a compound containing boron atoms to the patient and irradiating the affected area of the body with a neutron beam. The success of the therapy depends mainly on the delivery of the boron isotope (10B) to the tumor using an appropriate boron carrier. One of the boron carriers used is boronophenylalanine (BPA). Therefore, in research on the use of boron carriers, it is also important to know the mechanisms of its uptake by cells. Aim: To study the expression of LAT family genes in two melanoma (high melanotic WM115 and low melanotic WM266-4) cell lines and melanocytes (HEMa-Lp) which are responsible for the transport the BPA into cells. Methods: To normalize data from the transcriptomic analysis, the ratio of the median method was used. This allowed the samples to be compared with each other. Comparison metrics included log-fold change (LFC) values. The heatmap of LFC values and the cluster map were created. These graphs show the similarities and differences between the samples. Results: Transcriptomic data show that in melanocytes, LFC for SLC7A5 (LAT1) and SLC3A2 (4Fhc) was higher than in melanoma cell lines, which corresponded with their melanin content. Conclusion: Our results indicate overexpression of BPA transporter genes in normal cells (melanocytes), which may suggest the highest level of these proteins in melanocytes compared to less melanotic melanoma. Therefore, for BNCT, the use of BPA as the 10B carrier will require additional qualifying tests of amino acid transporter expression for patients and specific tumors to develop a personalized BNCT.
Comparison of qNANO results from the isolation of extracellular microvesicles with the theoretical model
M. Durak-Kozica, A. Wróbel, M. Platt, E. Stępień
abstract
Objectives: Extracellular vesicles (EVs) are heterogeneous membrane vesicles in diameter of 30-5000 nm, that transport proteins, non-coding RNAs (miRNAs), lipids and metabolites. Major populations include exosomes, ectosomes and apoptotic bodies. The purpose of this study was to compare the distribution of EVs obtained under different conditions of differential centrifugation, including ultracentrifugation, with the results developed based on a theoretical model. Methods: Immortalized endothelial cell line that expresses h-TERT (human telomerase) was used to release of EVs: microvascular TIME. EVs were isolated from the culture medium at different centrifugation parameters. The size distribution of the EVs was measured using TRPS technology on a qNano instrument. Surface markers were evaluated using flow cytometry. The isolated EV subpopulations were compared with the theoretical model developed by Livshits. Results: EVs isolated from endothelial cells show strong aggregating properties, which was confirmed by TEM, TRPS imaging and flow cytometry. Conclusions: Obtaining pure EV subpopulations is difficult because of the small differences in the diameter of ectosomes and exosomes, and the strong aggregating properties of EVs.
Proteomic profiling of exosomes derived from pancreatic beta-cells cultured under hyperglycemia
C. Rząca, U. Jankowska, E. Stępień
abstract
Introduction
Cargo carried by extracellular vesicles (EVs) is considered a promising diagnostic marker, especially proteins. EVs can be divided according to their size and way of biogenesis into exosomes (diameter < 200 nm) and ectosomes (diameter > 200 nm). Exosomes are considered to be of endocytic origin, and ectosomes are produced by budding and shedding from the plasma membrane [1].
Methods
The first step of this study was a characterization of the exosome sample. Using Tunable Resistive Pulse Sensing (qNano) size distribution and concentration were measured. The mean size of exosomes was 120?9.17 nm. In the present study, a nano liquid chromatography coupled with tandem mass spectrometry (nanoLC-MS/MS) was used to compare protein profiles of exosomes secreted by pancreatic beta cells (1.1B4) grown under normal glucose (NG, 5 mM D-glucose) and high glucose (HG, 25 mM D-glucose) conditions. The EV samples were lysed, and proteins were denatured, digested, and analyzed using a Q-Exactive mass spectrometer coupled with the UltiMate 3000 RSLC nano system. The nanoLC-MS/MS data were searched against the SwissProt Homo sapiens database using MaxQuant software and protein quantitation was done by the MaxLFQ algorithm. Statistical analysis was carried out with Perseus software. Further bioinformatic analysis was performed using the FunRich 3.1.4 software with the UniProt protein database and String [2].
Results
As a result of the nanoLC-MS/MS analysis more than 1,000 proteins were identified and quantified in each sample. The average number of identified proteins in exosomes was 1,397. Label-free quantitative analysis showed that exosome composition differed significantly between those isolated under NG and HG conditions. Many pathways were down-regulated in HG, particularly the ubiquitin-proteasome pathway. In addition, a significant up-regulation of the Ras-proteins pathway was observed in HG.
Conclusion
Our description of exosomes protein content and its related functions provides the first insight into the EV interactome and its role in glucose intolerance development and diabetic complications. The results also indicate the applicability of EV proteins for further investigation regarding their potential as circulating in vivo biomarkers.
Comparison of Lugol's solution and Fe3O4 nanoparticles as contrast agents for tumor spheroid imaging using microcomputed tomography
D. Panek, M. Szczepanek, B. Leszczyński, P. Moskal, E. Stępień
abstract
Background Lugol's solution is well known for its unique contrasting properties to biological samples in in microcomputed tomography imaging. On the other hand, iron oxide nanoparticles (IONPs), which have much lower attenuation capabilities to X-ray radiation show decent cell penetration and accumulation properties, are increasingly being used as quantitative contrast agents in biology and medicine. In our research, they were used to stain 3D cell structures called spheroids. Aim In this study, the micro computed tomography (microCT) technique was used to visualize and compare the uptake and accumulation of two contrast agents, Lugol's solution and iron (II, III) oxide nanoparticles (IONPs) in the in vitro human spheroid tumour model. Methods The metastatic human melanoma cell line WM266-4 was cultured, first under standard 2D conditions, and after reaching 90% confluence cells was seeded in a low adhesive plate, which allows spheroid formation. On the 7th day of growth, the spheroids were transferred to the tubes and stained with IONPs or Lugol's solution and subjected to microCT imaging. Results Our research allows visualization of the regions of absorption at the level of single cells, with relatively short incubation times - 24h - for Lugol's solution. IONPs proved to be useful only in high concentrations (1 mg/ml) and long incubation times (96h). Conclusions When comparing the reconstructed visualizations of the distribution of these stating agents, it is worth noting that Lugol's solution spreads evenly throughout the spheroids, whereas IONPs (regardless of their size 5 and 30 nm) accumulate only in the outer layer of the spheroid structure.
Multi-photon time-of-flight MLEM application for the positronium imaging in J-PET
R. Shopa, K. Dulski
abstract
We develop a positronium imaging method for the Jagiellonian PET (J-PET) scanners based on the time-of-flight maximum likelihood expectation maximisation (TOF MLEM). The system matrix elements are calculated on-the-fly for the coincidences comprising two annihilation and one de-excitation photons that originate from the ortho-positronium (o-Ps) decay. Using the Geant4 library, a Monte Carlo simulation was conducted for four cylindrical 22Na sources of ?+ decay with diverse o-Ps mean lifetimes, placed symmetrically inside the two JPET prototypes. The estimated time differences between the annihilation and the positron emission were aggregated into histograms (one per voxel), updated by the weights of the activities reconstructed by TOF MLEM. The simulations were restricted to include only the o-Ps decays into back-to-back photons, allowing a linear fitting model to be employed for the estimation of the mean lifetime from each histogram built in the log scale. To suppress the noise, the exclusion of voxels with activity below 2% ? 10% of the peak was studied. The estimated o-Ps mean lifetimes were consistent with the simulation and distributed quasi-uniformly at high MLEM iterations. The proposed positronium imaging technique can be further upgraded to include various correction factors, as well as be modified according to realistic o-Ps decay models.
Realistic Total-Body J-PET Geometry Optimization--Monte Carlo Study
J. Baran, W. Krzemień, L. Raczyński, M. Bała, A. Coussat, S. Parzych, N. Chug, E. Czerwiński, C. Oana Curceanu, M. Dadgar, K. Dulski, K. Eliyan, J. Gajewski, A. Gajos, B. Hiesmayr, K. Kacprzak, Ł. Kapłon, K. Klimaszewski, G. Korcyl, T. Kozik, D. Kumar, S. Niedźwiecki, D. Panek, E. Perez del Rio, A. Ruciński, S. Sharma, Shivani, R.Y. Shopa, M. Skurzok, E. Stępień, F. Tayefiardebili, K. Tayefiardebili, W. Wiślicki, P. Moskal
abstract
First Tests of the Full SIDDHARTA-2 Experimental Apparatus with a 4He Gaseous Target
A. Scordo, C. Amsler, M. Bazzi, D. Bosnar, M. Bragadireanu, M. Cargnelli, M. Carminati, A. Clozza, G. Deda, L. De Paolis, R. Del Grande, L. Fabbietti, C. Fiorini, C. Guaraldo, M. Iliescu, M. Iwasaki, A. Khreptak, P. King, P. Levi Sandri, S. Manti, J. Marton, M. Miliucci, P. Moskal, F. Napolitano, S. Niedźwiecki, H. Ohnishi, K. Piscicchia, Y. Sada, F. Sgaramella, H. Shi, M. Silarski, D.L. Sirghi, F. Sirghi, M. Skurzok, A. Spallone, K. Toho, M. Tüchler, O. Vazquez Doce, C. Yoshida, J. Zmeskal, C. Curceanu
abstract
In this paper, we present the first tests performed after the full installation of the SIDDHARTA-2 experimental apparatus on the interaction region of the DA?NE collider at the INFN National Laboratories of Frascati. Before starting the first measurement of the kaonic deuterium 2p->1s transition, an accurate evaluation of the background rejection was required, mainly achieved with the kaon trigger system. This run, performed in the period 04-26/05/2022 with a 4He gaseous target, confirmed the 105 order of magnitude of the rejection factor obtained with the reduced version of the setup and different machine conditions in 2021. This important outcome motivated the filling of the target cell with deuterium and the start of the measurement campaign of the kaonic deuterium 2p->1s transition.
The SIDDHARTA-2 calibration method for high precision kaonic atoms X-ray spectroscopy measurements
F. Sgaramella, M. Miliucci, M. Bazzi, D. Bosnar, M. Bragadireanu, M. Carminati, M. Cargnelli, A. Clozza, G. Deda, L. De Paolis, R. Del Grande, C. Fiorini, C. Guaraldo, M. Iliescu, M. Iwasaki, P. King, P. Levi Sandri, J. Marton, P. Moskal, F. Napolitano, S. Niedźwiecki, K. Piscicchia, A. Scordo, H. Shi, M. Silarski, D. Sirghi, F. Sirghi, M. Skurzok, A. Spallone, M. Tüchler, J. Zmeskal, C. Curceanu
abstract
The SIDDHARTA-2 experiment at the DAFNE collider aims to perform the first kaonic deuterium X-ray transitions to the fundamental level measurement, with a systematic error at the level of a few eV. To achieve this challenging goal the experimental apparatus is equipped with 384 Silicon Drift Detectors (SDDs) distributed around its cryogenic gaseous target. The SDDs developed by the SIDDHARTA-2 collaboration are suitable for high precision kaonic atoms spectroscopy, thanks to their high energy and time resolutions combined with their radiation hardness. The energy response of each detector must be calibrated and monitored to keep the systematic error, due to processes such as gain fluctuations, at the level of 2-3 eV. This paper presents the SIDDHARTA-2 calibration method which was optimized during the preliminary phase of the experiment in the real background conditions of the DAFNE collider, which is a fundamental tool to guarantee the high precision spectroscopic performances of the system over long periods of data taking, as that required for the kaonic deuterium measurement.
Kaonic Atoms at the DAFNE Collider with the SIDDHARTA-2 Experiment
F. Napolitano, F. Sgaramella, M. Bazzi, D. Bosnar, M. Bragadireanu, M. Carminati, M. Cargnelli, A. Clozza, G. Deda, L. De Paolis, R. Del Grande, L. Fabbietti, C. Fiorini, C. Guaraldo, M. Iliescu, M. Iwasaki, P. Levi Sandri, J. Marton, M. Miliucci, P. Moskal, S. Niedźwiecki, K. Piscicchia, A. Scordo, H. Shi, D. Sirghi, F. Sirghi, M. Silarski, M. Skurzok, A. Spallone, M. Tüchler, J. Zmeskal, C. Curceanu
abstract
Kaonic atoms are a unique tool to explore quantum chromodynamics in the strangeness sector at low energy, with implications reaching neutron stars and dark matter. Precision X-ray spectroscopy can fully unlock the at-threshold isospin dependent antikaon-nucleon scattering lengths, via the atomic transitions to the fundamental level. While the SIDDHARTA experiment at the INFN-LNF DAFNE collider successfully measured kaonic hydrogen, its successor SIDDHARTA-2 is starting now its data taking campaign aiming to finally fully disentangle the isoscalar and isovector scattering lengths via the measurement of kaonic deuterium. An overview of the first experimental results from a preparatory run for the SIDDAHARTA-2 experiment is presented.
Radiovesicolomics - new approach in medical imaging
E.Ł. Stępień, C. Rząca, P. Moskal
abstract
This review introduce extracellular vesicles (EVs) to a molecular imaging field. The idea of modern analyses based on the use of omics studies, using highthroughput methods to characterize the molecular content of a single biological system, vesicolomics seems to be the new approach to collect molecular data about EV content, to find novel biomarkers or therapeutic targets. The use of various imaging techniques, including those based on radionuclides as positron emission tomography (PET) or single photon
emission computed tomography (SPECT), combining molecular data on EVs, opens up the new space for radiovesicolomics?a new approach to be used in theranostics.
Investigation of novel preclinical Total Body PET designed with J-PET technology: A simulation study
M. Dadgar, S. Parzych, F. Tayefi Ardebili, J. Baran, N. Chug, C. Curceanu, E. Czerwiński, K. Dulski, K. Eliyan, A. Gajos, B.C. Hiesmayr, K. Kacprzak, K. Klimaszewski, P. Konieczka, G. Korcyl, T. Kozik, W. Krzemień, D. Kumar, S. Niedźwiecki, D. Panek, E. Perez del Rio, L. Raczyński, S. Sharma, R.Y. Shopa, M. Skurzok, K. Tayefi Ardebili, S. Vandenberghe, W. Wiślicki, E.Ł. Stępień, P. Moskal
abstract
The growing interest in human-grade Total Body PET systems has also application in small animal research. Due to the existing limitations in human-based studies involving drug development and novel treatment monitoring, animalbased research became a necessary step for testing and protocol preparation. In this simulation-based study two unconventional, cost effective small animal Total Body PET scanners (for mouse and rat studies) have been investigated in order to inspect their feasibility for preclinical research. They were designed with the novel technology explored by the Jagiellonian PET Collaboration (J-PET). Two main PET characteristics: sensitivity and spatial resolution were mainly inspected to evaluate their performance. Moreover, the impact of the scintillator dimension and time-offlight on the latter parameter were examined in order to design the most efficient tomographs. The presented results show that for mouse TB J-PET the achievable system sensitivity is equal to 2.35% and volumetric spatial resolution to 9.46 +- 0.54 mm3, while for rat TB J-PET they are equal to 2.6% and 14.11 ? 0.80 mm3, respectively. Furthermore, it was shown that the designed tomographs are almost parallax-free systems, hence they resolve the problem of the acceptance criterion trade-off between enhancing spatial resolution and reducing sensitivity.
ProTheRaMon - a GATE simulation framework for proton therapy range monitoring using PET imaging
D. Borys, J. Baran, K.W. Brzezinski, J. Gajewski, N. Chug, A. Coussat, E. Czerwiński, M. Dadgar, K. Dulski, K. Valsan Eliyan, A. Gajos, K. Kacprzak, Ł. Kapłon, K. Klimaszewski, P. Konieczka, R. Kopec, G. Korcyl, T. Kozik, W. Krzemień, D. Kumar, A. John Lomax, K. McNamara, S. Niedźwiecki, P. Olko, D. Panek, S. Parzych, E. Pérez del Río, L. Raczyński, S. Sharma, S. Shivani, R.Y. Shopa, T. Skóra, M. Skurzok, P. Stasica, E. Stępień, K. Tayefi Ardebili, F. Tayefi, D. Charles Weber, C. Winterhalter, W. Wiślicki, P. Moskal, A. Rucinski
abstract
Objective: This paper reports on the implementation and shows examples of the use of the ProTheRaMon framework for simulating the delivery of proton therapy treatment plans and range monitoring using positron emission tomography (PET). ProTheRaMon offers complete processing of proton therapy treatment plans, patient CT geometries, and intra-treatment PET imaging, taking into account therapy and imaging coordinate systems and activity decay during the PET imaging protocol specific to a given proton therapy facility. We present the ProTheRaMon framework and illustrate its potential use case and data processing steps for a patient treated at the Cyclotron Centre Bronowice (CCB) proton therapy center in Krakow, Poland. Approach: The ProTheRaMon framework is based on GATE Monte Carlo software, the CASToR reconstruction package and in-house developed Python and bash scripts. The framework consists of five separated simulation and data processing steps, that can be further optimized according to the user's needs and specific settings of a given proton therapy facility and PET scanner design. Main results: ProTheRaMon is presented using example data from a patient treated at CCB and the J-PET scanner to demonstrate the application of the framework for proton therapy range monitoring. The output of each simulation and data processing stage is described and visualized. Significance: We demonstrate that the ProTheRaMon simulation platform is a high-performance tool, capable of running on a computational cluster and suitable for multi-parameter studies, with databases consisting of large number of patients, as well as different PET scanner geometries and settings for range monitoring in a clinical environment. Due to its modular structure, the ProTheRaMon framework can be adjusted for different proton therapy centers and/or different PET detector geometries. It is available to the community via github.
Perspectives on translation of positronium imaging into clinics
P. Moskal, E.Ł. Stępień
abstract
The image of positronium properties created in the patient?s body during PET examination tells about the inter- and intra-molecular structure of the tissue and the concentration of bio-active molecules in the tissue [2?4]. In this article, we advocate the opinion that total-body PET systems, thanks to their high imaging sensitivity and high time resolution, open up the prospect of translating
positronium imaging into clinics.
Investigation of the light output of 3D-printed plastic scintillators for dosimetry applications
Ł. Kapłon, D. Kulig, S. Beddar, T. Fiutowski, W. Górska, J. Hajduga, P. Jurgielewicz, D. Kabat, K. Kalecińska, M. Kopeć, S. Koperny, B. Mindur, J. Moroń, G. Moskal, S. Niedźwiecki, M. Silarski, F. Sobczuk, T. Szumlak, A. Ruciński
abstract
Three-dimensional (3D) printing, specifically digital light processing (DLP) technique, can be used to manufacture plastic scintillators of any shape. The purpose of this study was to determine the light output of DLP 3Dprinted scintillators for dosimetry applications. Two types of plastic scintillators with dimensions 10 mm × 10 mm × 10 mm were fabricated using DLP 3D-printing at Hanyang University, South Korea. The light output of these DLP 3D-printed samples was measured and compared to that of a commercial plastic scintillator of the same dimensions, RP-408, produced by casting. The 3D-printed scintillators emitting violet and blue light had a lower relative light output by 49% and 43%, respectively, compared to the RP-408 reference scintillator. We also investigated three types of scintillator surface finishing methods: the original surface made by the 3D printer, a sanded surface, and a polished surface. Furthermore, three wrapping configurations were tested: bare scintillator, diffuse-type polytetrafluoroethylene tape, and specular-type enhanced specular reflector foil. Both reflector types, diffuse and specular, reflected blue light with comparable efficiency. Additionally, emission and transmission spectra of the samples were measured. Emission maxima were located at 430 nm for RP-408, and 438 and 475 nm for two 3D-printed samples. Transmittance at the wavelength of maximum emission was equal to 89% for RP-408, and 73% and 66% for the two DLP-printed samples. Although the light output of the 3D-printed scintillators was about 50% lower than that of the commercial plastic scintillator, due to characteristics of 3Dprinted plastic scintillators, i.e. fast, low-cost production, and easy customization of the printed shape, they are promising as an active part of dosimeters for use in high intensity gamma radiation fields produced by medical linear accelerators with acceptable signal-to-noise ratio level.
Decoherence Puzzle in Measurements of Photons Originating from Electron-Positron Annihilation
S. Sharma, D. Kumar, P. Moskal
abstract
The entanglement of photons originating from electron-positron annihilation has not been experimentally proven. owever, the independent experiments performed so far unanimously confirm that the correlation between the linear polarizations of back-to-back photons from electron?positron annihilation is
consistent with the assumption that these photons are entangled in the polarization. Yet, unexpectedly,
recent experiments differ as regards the correlation of polarization direction of back-to-back photons
after the decoherence induced by the scattering of one of these photons on the electron in the scattering
material. In one of the experiments, the correlation before and after the decoherence of the photon state
is the same, and in the other experiment, the scattering of one photon leads to a significant decrease
in this correlation. Here we discuss this puzzle. Decoherent states were ensured provided by forcing
one of the annihilation photons to scatter earlier before measuring the polarization correlation based
on Compton kinematics. The comparison is made between the experimental setups used for the different measurements, and the results obtained are briefly discussed, highlighting the parameters that are
important in performing such measurements. Finally, the main features of the J-PET detector are presented, along with the schemes for performing similar studies, so that the conclusive results can be used
as remarks to solve the puzzle in question. Solving the decoherence puzzle will have crucial consequences
for basic studies of entanglement, as well as for the proposed application of the photon polarization in
positron emission tomography. If the correlation of the polarization of back-to-back photons from the
electron?positron annihilation is the same before and after the scattering of these photons, then it will
not be useful for the reduction of scatter fraction in positron emission tomography diagnostics.
Mirror Matter Searches with the J-PET Detector
E. Pérez del Río, W. Krzemień, B. Kłósek
abstract
The positronium system ? a bound state of an electron and a positron ? is suitable for testing the
predictions of quantum electrodynamics, since its properties can be perturbatively calculated to high
accuracy and, unlike the hydrogen system, it is not affected by the finite size or quantum chromodynamics effects at the current level of experimental precision. Experiments searching for invisible decays
of the positronium triplet state ? the ortho-positronium ? which mainly decays to three photons, are
being conducted since they are sensitive to new physics scenarios, e.g., mirror matter, milli-charged
particles, and extra space-time dimensions. The particular case of mirror matter and its search with
the novel total-body positron emission tomography scanner at the Jagiellonian University is presented.
This J-PET is a large, high precision medical imaging tool based on plastic scintillators.
Development of the Normalization Method for the Jagiellonian PET Scanner
A. Coussat, W. Krzemien, J. Baran, S. Parzych
abstract
This work aims at applying the theory of the component-based normalization to the Jagiellonian PET
scanner, currently under development at the Jagiellonian University. In any positron emission tomography acquisition, efficiency along a line-of-response can vary due to several physical and geometrical
effects, leading to severe artifacts in the reconstructed image. To mitigate these effects, a normalization
coefficient is applied to each line-of-response, defined as the product of several components. The specificity of the Jagiellonian PET scanner geometry is taken into account. The results obtained from the
GATE simulations are compared with the preliminary results obtained from the experimental data.
Towards the first kaonic deuterium measurement with the SIDDHARTA-2 experiment at DAFNE
M. Miliucci, M. Bazzi, D. Bosnar, M. Bragadireanu, M. Carminati, M. Cargnelli, A. Clozza, C. Curceanu, G. Deda, L. De Paolis, R. Del Grande, C. Fiorini, C. Guaraldo, M. Iliescu, M. Iwasaki, P. King, P. Levi Sandri, J. Marton, P. Moskal, F. Napolitano, S. Niedźwiecki, K. Piscicchia, A. Scordo, F. Sgaramella, H. Shi, M. Silarski, D. Sirghi, F. Sirghi, M. Skurzok, A. Spallone, M. Tüchler, J. Zmeskal
abstract
The SIDDHARTA-2 experiment is going to perform the longawaited
high precision X-ray measurement of kaonic deuterium, obtaining for the
first time the values of the shift and the width induced by the strong interaction
on the fundamental level. By combining this unprecedented result with the
analogous kaonic hydrogen measurement performed by the SIDDHARTA experiment,
it will be possible to extract the isospin-dependent antikaon-nucleon scattering
lengths, providing direct information on the Quantum Chromodynamics (QCD)
in the non-perturbative Chromodynamics (QCD) in the non-perturbative regime
in the strangeness sector. This paper describes the SIDDHARTA-2 experiment,
presently installed at the DA?NE collider of Istituto Nazionale di Fisica Nucleare -
Laboratori Nazionali di Frascati, and the results obtained during the kaonic helium
run, preparatory for the kaonic deuterium data taking campaign planned for 2022.
The eta- and eta'-nucleus interactions and the search for eta, eta'- mesic states
S. D. Bass, V. Metag, P. Moskal
abstract
The isoscalar eta and eta? mesons are special in QCD, being linked both to chiral symmetry and to non-perturbative glue associated with the axial anomaly. The properties of these mesons in medium are sensitive to how these dynamics work in the nuclear environment. In contrast to pionic and kaonic atoms which are mainly bound by the Coulomb interaction with some corrections due to the strong force (Coulomb assisted binding), the eta and eta' as neutral mesons can only be bound by the strong interaction. Is this interaction strong enough? This topic has inspired a vigorous program of experiments, conducted in close contact with theory, One has to determine the complex eta, eta'-nucleus potential. Does the real part V provide a sufficiently deep potential? Is the imaginary part W small enough to allow for narrow states that can more easily be detected experimentally, i.e. |W|<<|V|? The eta' effective mass is observed to be suppressed by ~40 MeV at nuclear matter density. Bound state searches are ongoing. This article gives an overview of the status of knowledge in this field together with an outlook to future experiments.
Real-Time data processing pipeline for trigger readout board-based data acquisition systems
A. Malige, G. Korcyl, M. Firlej, T. Fiutowski, M. Idzik, B. Korzeniak, R. Lalik, A. Misiak, A. Molenda, J. Moroń, N. Rathod, P. Salabura, K. Świentek, P. Wintz
abstract
Large-scale physics experiments running at high interaction rates place a high demand on the data acquisition system (DAQ) responsible for transporting the data from the detector to the storage. The antiProton ANihilation at DArmstadt (PANDA) at the facility for anti-proton and ion research (FAIR) is one such experiment of the future that will not use fixed hardware triggers; instead, the event selection is based on real-time feature extraction, filtering, and high-level correlations. A firmware framework for such real-time data processing has been developed and tested with hardware setup for a PANDA Forward Tracker (FT) prototype. The solution is applicable for other detector subsystems based on the so-called Trigger Readout Board (TRB) data read-out system.
Large area silicon drift detectors system for high precision timed x-ray spectroscopy
M. Miliucci, M. Iliescu, F. Sgaramella, M. Bazzi, D. Bosnar, M. Bragadireanu, M. Carminati, M. Cargnelli, A. Clozza, C. Curceanu, G. Deda, L. De Paolis, R. Del Grande, C. Fiorini, C. Guaraldo, M. Iwasaki, P. King, P. Levi Sandri, J. Marton, P. Moskal, F. Napolitano, S. Niedźwiecki, K. Piscicchia, A. Scordo, H. Shi, M. Silarski, D. Sirghi, F. Sirghi, M. Skurzok, A. Spallone, M. Tüchler, O. Vazquez Doce and J. Zmeskal
abstract
The current work presents the optimization of large area silicon drift detectors developed by the SIDDHARTA-2 collaboration for high precision x-ray measurements of light exotic atom transitions. Two different radiation sources were employed in the study: an x-ray tube, for investigating the energy resolution and the charge collection efficiency of the device in the range 4000 eV-13000 eV, and a beta-90Sr radioactive source for measuring the timing response, thus qualifying the charge drift parameters inside the semiconductor. The study reports the spectroscopic response optimization, together with the tuning of the electron dynamics for the given Silicon technology, by adjusting the applied electric field and the working temperature, which allow a good control of the device's performances for high precision, timed x-ray spectroscopy applications.
Precision tests of quantum mechanics and CPT symmetry with entangled neutral kaons at KLOE
D. Babusci, M. Berlowski, C. Bloise, F. Bossi, P. Branchini, A. Budano, B. Cao, F. Ceradini, P. Ciambrone, F. Curciarello, E. Czerwiński, G. D'Agostini, E. Dane, V. De Leo, E. De Lucia, A. De Santis, P. De Simone, A. Di Cicco, A. Di Domenico, E. Diociaiuti, D. Domenici, A. D'Uffizi, A. Fantini, G. Fantini, P. Fermani, S. Fiore, A. Gajos, P. Gauzzi, S. Giovannella, E. Graziani, V. L. Ivanov, T. Johansson, X. Kang, D. Kisielewska-Kamińska, E. A. Kozyrev, W. Krzemien, A. Kupsc, P. A. Lukin, G. Mandaglio, M. Martini, R. Messi, S. Miscetti, D. Moricciani, P. Moskal, A. Passeri, V. Patera, E. Perez del Rio, P. Santangelo, M. Schioppa, A. Selce, M. Silarski, F. Sirghi, E. P. Solodov, L. Tortora, G. Venanzoni, W. Wiślicki, M. Wolke
abstract
The quantum interference between the decays of entangled neutral kaons is studied in the process phi -> KSKL -> pi(+)pi(-)pi(+)pi(-), which exhibits the characteristic Einstein-Podolsky-Rosen correlations that prevent both kaons to decay into pi(+)pi(-) at the same time. This constitutes a very powerful tool for testing at the utmost precision the quantum coherence of the entangled kaon pair state, and to search for tiny decoherence and CPT violation effects, which may be justified in a quantum gravity framework.
The analysed data sample was collected with the KLOE detector at DAFNE, the Frascati phi-factory, and corresponds to an integrated luminosity of about 1.7 fb(-1), i.e. to about 1.7 x 10(9) phi -> KSKL decays produced. From the fit of the observed Delta t distribution, being Delta t the difference of the kaon decay times, the decoherence and CPT violation parameters of various phenomenological models are measured with a largely improved accuracy with respect to previous analyses.
The results are consistent with no deviation from quantum mechanics and CPT symmetry, while for some parameters the precision reaches the interesting level at which - in the most optimistic scenarios - quantum gravity effects might show up. They provide the most stringent limits up to date on the considered models.
A new kaonic helium measurement in gas by SIDDHARTINO at the DAFNE collider
D. Sirghi, F. Sirghi, F. Sgaramella, M. Bazzi, D. Bosnar, M. Bragadireanu, M. Carminati, M. Cargnelli, A. Clozza, G. Deda, L. De Paolis, R. Del Grande, L. Fabbietti, C. Fiorini, C. Guaraldo, M. Iliescu, M. Iwasaki, P. Levi Sandri, J. Marton, M. Miliucci, P. Moskal, F. Napolitano, S Niedźwiecki, K. Piscicchia, A. Scordo, H. Shi, M. Skurzok, M. Silarski, A. Spallone, M. Tüchler, O. Vazquez Doce, J. Zmeskal, C. Curceanu
abstract
The SIDDHARTINO experiment at the DAFNE Collider of INFN-LNF, the pilot run for the SIDDHARTA-2 experiment which aims to perform the measurement of kaonic deuterium transitions to the fundamental level, has successfully been concluded. The paper reports the main results of this run, including the optimization of various components of the apparatus, among which the degrader needed to maximize the fraction of kaons stopped inside the target, through measurements of kaonic helium transitions to the 2p level. The obtained shift and width values are epsilon_2p = E_exp-E_e.m = 0.2 pm 2.5(stat) pm 2(syst) eV and Gamma_2p = 8 pm 10 eV (stat), respectively. This new measuremnt of the shift, in particular, represents the most precise one for a gaseous target and is expected to contribute to a better understanding of the kaon-nuclei interaction at low energy.
Investigation of the low-energy K- hadronic interactions with light nuclei by AMADEUS
M. Skurzok, M. Bazzi, M. Bragadireanu, D. Bosnar, M. Cargnelli, A. Clozza, C. Curceanu, L. de Paolis, R. Del Grande, L. Fabbietti, C. Guaraldo, M. Iliescu, M. Iwasaki, P. Levi Sandri, J. Marton, M. Miliucci, P. Moskal, K. Piscicchia, A. Ramos, A. Scordo, M. Silarski, D.L. Sirghi, F. Sirghi, A. Spallone, O. Vazquez Doce, S. Wycech, J. Zmeskal
abstract
The aim of the AMADEUS collaboration is to provide new experimental constraints to the antikaon-nucleon (K-N) strong interaction in the regime of nonperturbative QCD, investigating the low-energy K- hadronic interactions with light nuclei like H, 4He, 9Be and 12C. The unique low-momentum kaon beam produced at the DAFNE collider is ideal to study K- nuclear captures, both at-rest and in-flight. The large acceptance KLOE detector, used as an active target, allows to achieve excellent position and momentum resolutions. In this work, a brief description of recent AMADEUS results is presented.
Silicon Drift Detectors' Spectroscopic Response during the SIDDHARTA-2 Kaonic Helium Run at the DAFNE Collider
M. Miliucci, M. Bazzi, D. Bosnar, M. Bragadireanu, M. Carminati, M. Cargnelli, A. Clozza, C. Curceanu, G. Deda, L. De Paolis, R. Del Grande, C. Fiorini, C. Guaraldo, M. Iliescu, M. Iwasaki, P. King, P. Levi Sandri, J. Marton, P. Moskal, F. Napolitano, S. Niedźwiecki, K. Piscicchia, A. Scordo, F. Sgaramella, H. Shi, M. Silarski, D. Sirghi, F. Sirghi, M. Skurzok, A. Spallone, M. Tüchler, O. Vazquez Doce, J. Zmeskal
abstract
A large-area silicon drift detectors (SDDs) system has been developed by the SIDDHARTA-2 collaboration for high precision light kaonic atom X-ray spectroscopy at the DAFNE collider of Istituto Nazionale di Fisica Nucleare-Laboratori Nazionali di Frascati. The SDDs' geometry and electric field configuration, combined with their read-out electronics, make these devices suitable for performing high precision light kaonic atom spectroscopy measurements in the background of the DA phi NE collider. This work presents the spectroscopic response of the SDDs system during the first exotic atoms run of SIDDHARTA-2 with kaonic helium, a preliminary to the kaonic deuterium data taking campaign. The SIDDHARTA-2 spectroscopic system has good energy resolution and a 2 mu s timing window which rejects the asynchronous events, scaling the background by a factor of 10-5. The results obtained for the first exotic atoms run of SIDDHARTA-2 prove this system to be ready to perform the challenging kaonic deuterium measurement.
Positronium as a biomarker of hypoxia
P. Moskal and E.Ł. Stępień
abstract
In this review article, we present arguments demonstrating that the advent of high sensitivity total-body PET systems and the invention of the method of positronium imaging, open realistic perspectives for the application of positronium as a biomarker forin-vivo assessment of the degree of hypoxia. Hypoxia is a state or condition, in which the availability of oxygen is not sufficient to support physiological processes in tissue and organs. Positronium is a meta-stable atom formed from electron and positron which is copiously produced in the intramolecular spaces in the living organisms undergoing positron emission tomography (PET). Properties of positronium, such as e.g., lifetime, depend on the size of intramolecular spaces and the concentration in them of oxygen molecules. Therefore, information on the partial pressure of oxygen (pO2) in the tissue may be derived from the positronium lifetime measurement. The partial pressure of oxygen differs between healthy and cancer tissues in the range from 10 to 50 mmHg. Such differences of pO2 result in the change of ortho-positronium lifetime e.g., in water by about 2?7 ps. Thus, the application of positronium as a biomarker of hypoxia requires the determination of the mean positronium lifetime with the resolution in the order of2 ps. We argue that such resolution is in principle achievable for organ-wise positronium imaging with the total-body PET systems.
New trends in theranostics
P. Moskal, E.Ł. Stępień
abstract
Novel biomarker and drug delivery systems for theranostics-extracellular vesicles
E.Ł. Stępień, C. Rząca, P. Moskal
abstract
Extracellular vesicles (EVs) are nano- and micro-sized double-layered membrane entities derivedfrom most cell types and released into biological fluids. Biological properties (cell-uptake, biocompatibility), and chemical (composition, structure) or physical (size, density) characteristics make EVs a good candidate for drug delivery systems (DDS). Recent advances in the field of EVs (e.g., scaling-up production, purification) and developments of new imaging methods (total-body positron emission tomography [PET]) revealed benefits ofradio labeled EVs in diagnostic and interventional medicine as a potential DDs in theranostics.
Unparalleled and revolutionary impact of PET imaging on research and day to day practice of medicine
A. Alavi, T.J. Werner, E.Ł. Stępień, P. Moskal
abstract
Positron emission tomography (PET) imaging is the most quantitative modality for assessing diseaseactivity at the molecular and cellular levels, and therefore, it allows monitoring its course and determining the efficacy of various therapeutic interventions. In this scientific communication, we describe the unparalleled and revolutionary impact of PET imaging on researchand day to day practice of medicine. We emphasize thecritical importance of the development and synthesis of novel radiotracers (starting from the enormous impactof F-Fluorodeouxyglucose (FDG) introduced by investigators at the University of Pennsylvania (PENN)) and PET instrumentation. These innovations have led to the total-body PET systems enabling dynamic and parametric molecular imaging of all organs in the body simultaneously. We also present our perspectives for future development of molecular imaging by multiphoton PET systems that will enable users to extract substantial information (owing to the evolving role of positronium imaging) about the related molecular and biological bases of various disorders, which are unachievable by the current PET imaging techniques.
Combined BNCT and PET for theranostics
M. Silarski, K. Dziedzic-Kocurek, M. Szczepanek
abstract
This short review summarizes the issue of boron distribution monitoring in boron neutron capture therapy (BNCT), which remains a serious drawback of this powerful oncological treatment. Here we present the monitoring methods that are presently used with particular emphasis on positron emission tomography (PET) which has the highest potential to be used for the real-time monitoring of boron biodistribution. We discuss the possibility of using present PET scanners to determine the boron uptake in vivo before the BNCT treatment with the use of p-boronphenylalanine (BPA) labeled with 18F isotope. Several examples of preclinical studies and
clinical trials performed with the use of [18F]FBPA are shown. We also discuss shortly the perspectives of using other radiotracers and boron carriers which may significantly improve the boron imaging with the use of the state-of-the-art Total-Body PET scanners providing a theranostic approach in the BNCT.
Positronium imaging with the novel multiphoton PET scanner
P. Moskal, K. Dulski, N. Chug, C. Curceanu, E. Czerwiński, M. Dadgar, J. Gajewski, A. Gajos, G. Grudzień, B.C. Hiesmayr, K. Kacprzak, Ł. Kapłon, H. Karimi, K. Klimaszewski, G. Korcyl, P. Kowalski, T. Kozik, N. Krawczyk, W. Krzemień, E. Kubicz, P. Małczak, S. Niedźwiecki, M. Pawlik-Niedźwiecka, M. Pędziwiatr, L. Raczyński, J. Raj, A. Ruciński, S. Sharma, Shivani, R.Y. Shopa, M. Silarski, M. Skurzok, E.Ł. Stępień, M. Szczepanek, F. Tayefi, W. Wiślicki
abstract
In vivo assessment of cancer and precise location of altered tissues at initial stages of molecular disorders are important diagnostic challenges. Positronium is copiously formed in the free molecular spaces in the patient?s body during positron emission tomography (PET). The positronium properties vary according to the size of inter- and intramolecular voids and the concentration of molecules in them such as, e.g., molecular oxygen, O2; therefore, positronium imaging may provide information about disease progression during the initial stages of molecular alterations. Current PET systems do not allow acquisition of positronium images. This study presents a new method that enables positronium imaging by simultaneous registration of annihilation photons and deexcitation photons from pharmaceuticals labeled with radionuclides. The first positronium imaging of a phantom built from cardiac myxoma and adipose tissue is demonstrated. It is anticipated that positronium imaging will substantially
enhance the specificity of PET diagnostics.
Testing CPT symmetry in ortho-positronium decays with positronium annihilation tomography
P. Moskal, A. Gajos, M. Mohammed, J. Chhokar, N. Chug, C. Curceanu, E. Czerwiński, M. Dadgar, K. Dulski, M. Gorgol, J. Goworek, B. Hiesmayr, B. Jasińska, K. Kacprzak, Ł. Kapłon, H. Karimi, D. Kisielewska, K. Klimaszewski, G. Korcyl, P. Kowalski, N. Krawczyk, W. Krzemień, T. Kozik, E. Kubicz, S. Niedźwiecki, S. Parzych, M. Pawlik-Niedźwiecka, L. Raczyński, J. Raj, S. Sharma, S. Choudhary, R. Shopa, A. Sienkiewicz, M. Silarski, M. Skurzok, E. Stepien, F. Tayefi, W. Wiślicki
abstract
Charged lepton system symmetry under combined charge, parity, and time-reversal transformation (CPT) remain scarcely tested. Despite stringent quantum-electrodynamic limits, discrepancies in predictions for the electron-positron bound state (positronium atom) motivate further investigation, including fundamental symmetry tests. While CPT noninvariance effects could be manifested in non-vanishing angular correlations between final-state photons and spin of annihilating positronium, measurements were previously limited by the knowledge of the latter. Here, we demonstrate tomographic reconstruction techniques applied to three-photon annihilations of ortho-positronium atoms to estimate their spin polarisation without a magnetic field or polarised positronium source. We use a plastic-scintillator-based positron-emission-tomography scanner to record ortho-positronium (o-Ps) annihilations with a single-event estimation of o-Ps spin and determine the complete spectrum of an angular correlation operator sensitive to CPT-violating effects. We find no violation at the precision level of 10^{-4}, with an over threefold improvement on the previous measurement.
Blue-emitting polystyrene scintillators for plastic scintillation dosimetry
Ł. Kapłon, G. Moskal
abstract
Objectives: Purpose of this research was to find the best blue-emitting fluorescent substance for plastic scintillator used for gamma radiation dosimetry. Scintillator should convert gamma radiation into blue light with high efficiency.
Methods: Plastic scintillators with fixed concentration of various fluorescent additives, called wavelength shifters, absorbing ultraviolet light and emitting blue light were manufactured by radical bulk polymerization of styrene. Light output were measured and compared to the light output of commercial plastic scintillator.
Results: Performed measurements of charge Compton spectra confirmed usefulness of majority of researched substances as wavelength shifters in plastic scintillators with emission maximum at blue range of visible light.
Conclusions: Plastic scintillation dosimeter may be constructed from manufactured polystyrene-based scintillators. Performance of synthesized scintillators is close to commercial polystyrene scintillators.
Simulating NEMA characteristics of the modular total-body J-PET scanner - an economic total-body PET from plastic scintillators
P. Moskal, P. Kowalski, R.Y. Shopa, L. Raczyński, J. Baran, N. Chug, C. Curceanu, E. Czerwiński, M. Dadgar, K. Dulski, A. Gajos, B.C. Hiesmayr, K. Kacprzak, Ł. Kapłon, D. Kisielewska, K. Klimaszewski, P. Kopka, G. Korcyl, N. Krawczyk, W. Krzemień, E. Kubicz, Sz. Niedźwiecki, Sz. Parzych, J. Raj, S. Sharma, S. Shivani, E. Stępień, F. Tayefi, W. Wiślicki
abstract
The purpose of the presented research is the estimation of the performance characteristics of the economic total-body Jagiellonian-PET system (TB-J-PET) constructed from plastic scintillators. The characteristics are estimated according to the NEMANU-2-2018 standards utilizing the GATE package. The simulated detector consists of 24 modules, each built out of 32 plastic scintillator strips
(each with a cross-section of 6 mm times 30 mm and length of 140 or 200 cm) arranged in two layers in regular 24-sided polygon circumscribing a circle with a diameter of 78.6 cm. For the TB-J-PET with an axial field-of-view (AFOV) of 200 cm, a spatial resolution (SRs) of 3.7mm (transversal) and 4.9mm (axial) are achieved. The noise equivalent count rate (NECR) peak of 630 kcps is expected at 30 kBq cc^-1. Activity concentration and the sensitivity at the center amount to 38 cps kBq^-1. The scatter fraction (SF) is estimated to 36.2 %. The values of SF and SR are comparable to those obtained for the state-of-the-art clinical PET scanners and the first total-body tomographs: uExplorer and PennPET.With respect to the standard PET systemswithAFOVin the range from16 to 26 cm, the TBJ-PET is characterized by an increase inNECRapproximately by a factor of 4 and by the increase of the whole-body sensitivity by a factor of 12.6 to 38. The time-of-flight resolution for the TB-J-PETis expected to be at the level ofCRT=240 ps fullwidth at half-maximum. For the TB-J-PETwith an AFOVof 140 cm, an image quality of the reconstructed images of a NEMAIEC phantom was presented with a contrast recovery coefficient and a background variability parameters. The increase of the whole-body sensitivity andNECRestimated for the TB-J-PET with respect to current commercial PETsystems makes the TB-J-PET a promising cost-effective solution for the broad clinical applications of total-body PET scanners. TB-J-PETmay constitutes an economic alternative for the crystal TB-PET scanners, since plastic scintillators are much cheaper than BGO or LYSO crystals and the axial arrangement of the strips significantly reduces the costs of readout electronics and SiPMs.
Low energy kaon-nuclei interaction at DAFNE: The SIDDHARTA-2 experiment
M. Miliucci, M. Bazzi, D. Bosnar, M. Bragadireanu, M. Carminati, M. Cargnelli, A. Clozza, C. Curceanu, G. Deda, L. De Paolis, R. Del Grande, C. Fiorini, C. Guaraldo, M. Iliescu, M. Iwasaki, P. King, P. Levi Sandri, J. Marton, P. Moskal, F. Napolitano, S. Niedźwiecki, K. Piscicchia, A. Scordo, F. Sgaramella, H. Shi, M. Silarski, D. Sirghi, F. Sirghi, M. Skurzok, A. Spallone, M. Tüchler, O. Vazquez Doce, J. Zmeskal
abstract
Light kaonic atoms spectroscopy is a unique tool for the investigation of the low-energy quantum chromodynamics (QCD) in the strangeness sector. The precise measurements of the X-ray emission from light kaonic atoms provide information on the kaon-nucleus interaction at the threshold without the need for an extrapolation as in the case of scattering experiments. In 2009, the SIDDHARTA Collaboration performed the most precise measurement of kaonic hydrogen (K - H) X-ray transition to the fundamental level. Nowadays, the SIDDHARTA-2 Collaboration is ready to perform the more challenging measurement of kaonic deuterium (K - d) 2p -> 1s transition. To achieve this unprecedented result, which is fundamental to extract the isospin-dependent antikaon-nucleon scattering lengths, an upgraded experimental apparatus with respect to the SIDDHARTA one was realized. This paper presents an overview of the SIDDHARTA-2 setup installed on the DAFNE collider of LNF-INFN and the first results obtained during the machine optimization phase, in preparation for the kaonic deuterium data taking campaign planned in 20212022.
The J-PET detector - a tool for precision studies of ortho-positronium decays
K. Dulski, S.D. Bass, J. Chhokar, N. Chug, C. Curceanu, E. Czerwiński, M. Dadgar, J. Gajewski, A. Gajos, M. Gorgol, R. Del Grande, B.C. Hiesmayr, B. Jasińska, K. Kacprzak, Ł. Kapłon, H. Karimi, D. Kisielewska, K. Klimaszewski, P. Kopka, G. Korcyl, P. Kowalski, T. Kozik, N. Krawczyk, W. Krzemień, E. Kubicz, P. Małczak, M. Mohammed, Sz. Niedźwiecki, M. Pałka, M. Pawlik-Niedźwiecka, M. Pędziwiatr, L. Raczyński7, J. Raj, A. Ruciński, S. Sharma, Shivani, R.Y. Shopa, M. Silarski, M. Skurzok, E. Ł. Stępień, F. Tayefi, W. Wiślicki, B. Zgardzińska, P. Moskal
abstract
The J-PET tomograph is constructed from plastic scintillator strips arranged axially in concentric cylindrical layers. It enables investigations of positronium decays by measurement of the time, position, polarization and energy deposited by photons in the scintillators, in contrast to studies conducted so far with crystal and semiconductor based detection systems where the key selection of events is based on the measurement of the photons energies. In this article we show that the J-PET tomography system constructed solely from plastic scintillator detectors is capable of exclusive measurements of the decays of ortho-positronium atoms. We present the first positronium production results and its lifetime distribution measurements. The obtained results prove the capability of the J-PET tomograph for (i) fundamental studies of positronium decays (in particular test of discrete symmetries in purely leptonic systems), (ii) positron annihilation lifetime spectroscopy, as well as (iii) molecular imaging diagnostics and (iv) observation of entanglement
Kaonic Atoms Measurements at DAFNE: SIDDHARTA-2 and Future Perspectives
C. Curceanu,, M. Miliucci, A. Scordo, M. Bazzi, D. Bosnar, M. Bragadireanu, M. Cargnelli, M. Carminati, A. Clozza, G. Deda, L. De Paolis, R. Del Grande, C. Fiorini, C. Guaraldo, M. Iliescu, M. Iwasaki, P. King, P. Levi Sandri, J. Marton, P. Moskal, F. Napolitano, S. Niedźwiecki, K. Piscicchia, F. Sgaramella, H. Shi, M. Silarski, D. Sirghi, F. Sirghi, M. Skurzok, A. Spallone, M. Tüchler, O. Vazquez Doce, J. Zmeskal
abstract
High precision light kaonic atoms X-ray spectroscopy is a unique tool for performing experiments equivalent to scattering at vanishing relative energies, to determine the antikaon-nucleus interaction at threshold without the need of extrapolation to zero energy. The SIDDHARTA-2 collaboration is going to perform the first measurement of kaonic deuterium transitions to the fundamental level, which is mandatory to extract the isospin dependent antikaon-nucleon scattering lengths. The SIDDHARTA-2 experiment is presently installed on the DA Phi NE collider of INFN-LNF. The preliminary results obtained during the machine commissioning phase in preparation for the kaonic deuterium data taking campaign, together with future perspectives for extreme precision kaonic atoms studies at DA Phi NE are presented.
A Simulation Study to Estimate Optimum LOR Angular Acceptance for the Image Reconstruction with the Total-Body J-PET
M. Dadgar, S. Parzych and F. Tayefi Ardebili
abstract
One of the directions in today's development of PET scanners is to increase their axial field of view (AFOV). Currently limited to several centimeters, AFOV of the clinically available PET tomographs results in a very low sensitivity (~1%) and requires an extended time for a scan of a whole human body. While these drawbacks are addressed in the so-called, Total Body PET concept (scanner with a significantly elongated field of view), it creates new challenges not only in the mechanical construction but also in image reconstruction and event selection. The possibility of taking into account of large-angle variety of lines of responses (LORs) contributes positively to the sensitivity of the tomograph. However, at the same time, the most oblique LORs have an unfavorable influence on the spatial resolution due to the parallax error and large contribution to the scatter fraction. This forces to determine a new factor -acceptance angle - which is a maximum azimuthal angle for which the LORs are still taken into image reconstruction. Correct determination of such factors is imperative to maximize the performance of a Total Body PET system since it introduces a trade-off between the two main characteristics of scanners: sensitivity and spatial resolution.
This work has been dedicated to the estimation of the optimal acceptance angle for the proposed by the Jagiellonian PET (J-PET) Collaboration Total Body tomograph. J-PET Collaboration introduces a novel, cost-effective approach to PET systems development with the use of organic scintillators. This simulation study provides evidence that the 45-degree acceptance angle cut can be an appropriate choice for the investigated scanner.
Optimisation of the event-based TOF filtered back-projection for online imaging in total-body J-PET
R.Y. Shopa, K. Klimaszewski, P. Kopka, P. Kowalski, W. Krzemień, L. Raczyński, W. Wiślicki, N. Chug, C. Curceanu, E. Czerwiński, M. Dadgar, K. Dulski, A. Gajos, B.C. Hiesmayr, K. Kacprzak, Ł. Kapłon, D. Kisielewska, G. Korcyl, N. Krawczyk, E. Kubicz, Sz. Niedźwiecki, J. Raj, S. Sharma, Shivani, E.Ł. Stępień, F. Tayefi, P. Moskal
abstract
We perform a parametric study of the newly developed time-of-flight (TOF) image reconstruction algorithm, proposed for the real-time imaging in total-body Jagiellonian PET (J-PET) scanners. The asymmetric 3D filtering kernel is applied at each most likely position of electron-positron annihilation, estimated from the emissions of back-to-back gamma-photons. The optimisation of its parameters is studied using Monte Carlo simulations of a 1-mm spherical source, NEMA IEC and XCAT phantoms inside the ideal J-PET scan- ner. The combination of high-pass filters which included the TOF filtered back-projection (FBP), resulted in spatial resolution, 1.5 times higher in the axial direction than for the conventional 3D FBP. For real- istic 10-minute scans of NEMA IEC and XCAT, which require a trade-offbetween the noise and spatial resolution, the need for Gaussian TOF kernel components, coupled with median post-filtering, is demon- strated. The best sets of 3D filter parameters were obtained by the Nelder-Mead minimisation of the mean squared error between the resulting and reference images. The approach allows training the recon- struction algorithm for custom scans, using the IEC phantom, when the temporal resolution is below 50 ps. The image quality parameters, estimated for the best outcomes, were systematically better than for the non-TOF FBP.
Advanced Monte Carlo simulations of emission tomography imaging systems with GATE
D. Sarrut, M. Bała, M. Bardies, J. Bert, M. Chauvin, K. Chatzipapas, M. Dupont, A. Etxebeste, L.M. Fanchon, S. Jan, G. Kayal, A.S. Kirov, P. Kowalski, W. Krzemien, J. Labour, M. Lenz, G. Loudos, B. Mehadji, L. Ménard, C. Morel, P. Papadimitroulas, M. Rafecas, J. Salvadori, D. Seiter, M. Stockhoff, E. Testa, C. Trigila, U. Pietrzyk, S. Vandenberghe, M.A. Verdier, D. Visvikis, K. Ziemons, M. Zvolský, E. Roncali
abstract
Built on top of the Geant4 toolkit, GATE is collaboratively developed for more than 15 years to design Monte Carlo simulations of nuclear-based imaging systems. It is, in particular, used by researchers and industrials to design, optimize, understand and create innovative emission tomography systems. In this paper, we reviewed the recent developments that have been proposed to simulate modern detectors and provide a comprehensive report on imaging systems that have been simulated and evaluated in GATE. Additionally, some methodological developments that are not specific for imaging but that can improve detector modeling and provide computation time gains, such as Variance Reduction Techniques and Artificial Intelligence integration, are described and discussed.
Study of excited Xi baryons with the PANDA detector
G. Barucca, F. Davi, G. Lancioni, P. Mengucci, L. Montalto, P. P. Natali, N. Paone, D. Rinaldi, L. Scalise, B. Krusche, M. Steinacher, Z. Liu, C. Liu, B. Liu, X. Shen, S. Sun, G. Zhao, J. Zhao, M. Albrecht, W. Alkakhi, S. Bökelmann, S. Coen, F. Feldbauer, M. Fink, J. Frech, V. Freudenreich, M. Fritsch, J. Grochowski, R. Hagdorn, F. H. Heinsius, T. Held, T. Holtmann, I. Keshk, H. Koch, B. Kopf, M. Kümmel, M. Küßner, J. Li, L. Linzen, S. Maldaner, J. Oppotsch, S. Pankonin, M. Pelizä, S. Pflüger, J. Reher, G. Reicherz, C. Schnier, M. Steinke, T. Triffterer, C. Wenzel, U. Wiedner, H. Denizli, N. Er, U. Keskin, S. Yerlikaya, A. Yilmaz, R. Beck, V. Chauhan, C. Hammann, J. Hartmann, B. Ketzer, J. Müllers, B. Salisbury, C. Schmidt, U. Thoma, M. Urban, A. Bianconi, M. Bragadireanu, D. Pantea, M. Domagala, G. Filo, E. Lisowski, F. Lisowski, M. Michałek, P. Poznański, J. Płażek, K. Korcyl, P. Lebiedowicz, K. Pysz, W. Schäfer, A. Szczurek, M. Firlej, T. Fiutowski, M. Idzik, J. Moron, K. Swientek, P. Terlecki, G. Kor
abstract
The study of baryon excitation spectra provides insight into the inner structure of baryons. So far, most of the worldwide efforts have been directed towards N* and Delta spectroscopy. Nevertheless, the study of the double and triple strange baryon spectrum provides independent information to the N* and Delta spectra. The future antiproton experiment PANDA will provide direct access to final states containing a XiXi pair, for which production cross sections up to microbarn are expected in p(anti)p reactions. With a luminosity of L=10^31 cm^2 s^-1 in the first phase of the experiment, the expected cross sections correspond to a production rate of ~10^6 events /day . With a nearly 4pi detector acceptance, PANDA will thus be a hyperon factory. In this study, reactions of the type p(anti)p -> Xi+Xi*- as well as p(anti)p -> Xi*+ Xi- with various decay modes are investigated. For the exclusive reconstruction of the signal events, a full decay tree fit is used, resulting in reconstruction efficiencies between 3 and 5%. This allows high statistics data to be collected within a few weeks of data taking.
The potential of Lambda and Xi- studies with PANDA at FAIR
G. Barucca, F. Davi, G. Lancioni, P. Mengucci, L. Montalto, P. P. Natali, N. Paone, D. Rinaldi, L. Scalise, W. Erni, B. Krusche, M. Steinacher, N. Walford, N. Cao, Z. Liu, C. Liu, B. Liu, X. Shen, S. Sun, J. Tao, X. A. Xiong, G. Zhao, J. Zhao, M. Albrecht, W. Alkakhi, S. Bökelmann, F. Feldbauer, M. Fink, J. Frech, V. Freudenreich, M. Fritsch, R. Hagdorn, F. H. Heinsius, T. Held, T. Holtmann, I. Keshk, H. Koch, B. Kopf, M. Kuhlmann, M. Kümmel, M. Küßner, J. Li, A. Mustafa, M. Pelizäus, A. Pitka, J. Reher, G. Reicherz, M. Richter, C. Schnier, L. Sohl, M. Steinke, T. Triffterer, C. Wenzel, U. Wiedner, H. Denizli, N. Er, R. Beck, C. Hammann, J. Hartmann, B. Ketzer, J. Müllers, M. Rossbach, B. Salisbury, C. Schmidt, U. Thoma, M. Urban, A. Bianconi, M. Bragadireanu, D. Pantea, M. Domagala, G. Filo, E. Lisowski, F. Lisowski, M. Michałek, P. Poznański, J. Płażek, K. Korcyl, A. Kozela, P. Lebiedowicz, K. Pysz, W. Schäfer, A. Szczurek, T. Fiutowski, M. Idzik, K. Swientek, P. Terlecki, G. Korcyl, R. Lalik, A. Malige, P. Moskal, K. Nowakowski, W. Przygoda, N. Rathod, Z. Rudy, P. Salabura, J. Smyrski, I. Augustin, R. Böhm, I. Lehmann, L. Schmitt, V. Varentsov, M. Al-Turany, A. Belias, H. Deppe, R. Dzhygadlo, H. Flemming, A. Gerhardt, K. Götzen, A. Heinz, P. Jiang, R. Karabowicz, S. Koch, U. Kurilla, D. Lehmann, J. Lühning, U. Lynen, H. Orth, K. Peters, J. Rieger, T. Saito, G. Schepers, C. J. Schmidt, C. Schwarz, J. Schwiening, A. Täschner, M. Traxler, B. Voss, P. Wieczorek, V. Abazov, G. Alexeev, V. A. Arefiev, V. Astakhov, M. Yu. Barabanov, B. V. Batyunya, V. Kh. Dodokhov, A. Efremov, A. Fechtchenko, A. Galoyan, G. Golovanov, E. K. Koshurnikov, Y. Yu. Lobanov, A. G. Olshevskiy, A. A. Piskun, A. Samartsev, S. Shimanski, N. B. Skachkov, A. N. Skachkova, E. A. Strokovsky, V. Tokmenin, V. Uzhinsky, A. Verkheev, A. Vodopianov, N. I. Zhuravlev, D. Branford, D. Watts, M. Böhm, W. Eyrich, A. Lehmann, D. Miehling, M. Pfaffinger, N. Quin, L. Robison, K. Seth, T. Xiao, D. Bettoni, A. Ali, A. Hamdi, M. Himmelreich, M. Krebs, S. Nakh
abstract
he antiproton experiment PANDA at FAIR is designed to bring hadron physics to a new level in terms of scope, precision and accuracy. In this work, its unique capability for studies of hyperons is outlined. We discuss ground-state hyperons as diagnostic tools to study non-perturbative aspects of the strong interaction, and fundamental symmetries. New simulation studies have been carried out for two benchmark hyperon-antihyperon production channels: p(anti)p -> Lambda(anti)Lambda and p(anti)p -> anti(Xi)+Xi-. The results, presented in detail in this paper, show that hyperon-antihyperon pairs from these reactions can be exclusively reconstructed with high efficiency and very low background contamination. In addition, the polarisation and spin correlations have been studied, exploiting the weak, self-analysing decay of hyperons and antihyperons. Two independent approaches to the finite efficiency have been applied and evaluated: one standard multidimensional efficiency correction approach, and one efficiency independent approach. The applicability of the latter was thoroughly evaluated for all channels, beam momenta and observables. The standard method yields good results in all cases, and shows that spin observables can be studied with high precision and accuracy already in the first phase of data taking with PANDA.
Silicon Drift Detectors system for high precision light kaonic atoms spectroscopy
M. Miliucci, A. Scordo, D. Sirghi, A. Amirkhani, A. Baniahmad, M. Bazzi, D. Bosnar, M. Bragadireanu, M. Carminati, M. Cargnelli, A. Clozza, C. Curceanu, L. De Paolis, R. Del Grande, C. Fiorini, C. Guaraldo, M. Iliescu, M. Iwasaki, P. Levi Sandri, J. Marton, P. Moskal, F. Napolitano, S. Niedźwiecki, K. Piscicchia, F. Sgaramella, H. Shi, M. Silarski, F. Sirghi, M. Skurzok, A. Spallone, M. Tüchler, O. Vazquez Doce, J. Zmeskal
abstract
A large area Silicon Drift Detectors (SDDs) system and its readout electronics have been developed by the SIDDHARTA-2 Collaboration, aiming to perform high precision light kaonic atoms X-ray spectroscopy for the investigation of the ?-N strong interaction in the low-energy QCD regime. To perform these measurements, a linear energy response and a good energy resolution are mandatory requirements for the system, to be preserved along the whole DAQ (analog and digital) chain; such task is made even harder in the experimental environment of particles colliders, where the high background due to ionizing particles and radiation is present. The energy response of the SDDs system has been characterized with the beam-originating background generated during the commissioning phase of the DAFNE electron-positron collider (INFN-LNF) in early 2020. The data analysis has been optimized to describe the system's response and the background. The calibration procedure demonstrates that, despite the high and variable background of the collider, the energy response of the system is linear at the level of few eV (?E/E <10e-3), with an energy resolution of 157.8?0.3(+0.2)(-0.2)eV for the Fe Kalpha line.
On the K- Absorptions in Light Nuclei by AMADEUS
R. Del Grande, K. Piscicchia, M. Cargnelli, L. Fabbietti, J. Marton, P. Moskal, A. Ramos, A. Scordo, D. Sirghi, M. Skurzok, O.Vazquez Doce, S. Wycech, J. Zmeskal, P. Branchini, E. Czerwinski, V. De Leo, E. De Lucia, A. Di Cicco, E. Diociaiuti, R. Donghia, P. Fermani, S. Fiore, M. Martini, E.Perez Del Rio, A. Selce, M. Silarski, C. Curceanu
abstract
The aim of the AMADEUS collaboration is to provide experimental information on the low-energy
strong interaction of antikaons with nucleons, exploiting the absorptions of low momentum K- mesons
(pK ~127 MeV/c) produced at the DANE collider, in the materials composing the KLOE detector setup, used
as an active target. The K- single and multi-nucleon absorptions in light nuclei (4He and 12C) are investigated
by reconstructing hyperon?pion, hyperon?nucleon/nucleus pairs, emitted in the final state of the reactions. In
this paper the results obtained from the study of pi-, p and t correlated production are presented.
PANDA Phase One
G. Barucca, ..., G. Korcyl, R. Lalik, A. Malige, P. Moskal , K. Nowakowski , W. Przygoda , N. Rathod , P. Salabura , J. Smyrski , et al.
abstract
The Facility for Antiproton and Ion Research (FAIR) in Darmstadt, Germany, provides unique possibilities for a new generation of hadron-, nuclear- and atomic physics experiments. The future antiProton ANnihilations at DArmstadt (PANDA or P(anti)P PANDA) experiment at FAIR will offer a broad physics programme, covering different aspects of the strong interaction. Understanding the latter in the non-perturbative regime remains one of the greatest challenges in contemporary physics. The antiproton-nucleon interaction studied with PANDA provides crucial tests in this area. Furthermore, the high-intensity, low-energy domain of PANDA allows for searches for physics beyond the Standard Model, e.g. through high precision symmetry tests. This paper takes into account a staged approach for the detector setup and for the delivered luminosity from the accelerator. The available detector setup at the time of the delivery of the first antiproton beams in the HESR storage ring is referred to as the Phase One setup.The physics programme that is achievable during Phase One is outlined in this paper.
Synchronisation and calibration of the 24-modules J-PET prototype with 300 mm axial field of view
P. Moskal, T. Bednarski, Sz. Niedźwiecki, M. Silarski, E. Czerwiński, T. Kozik, J. Chhokar, M. Bała, C. Curceanu, R. Del Grande, M. Dadgar, K. Dulski, A. Gajos, M. Gorgol, N. Gupta-Sharma, B. C. Hiesmayr, B. Jasińska, K. Kacprzak, Ł. Kapłon, H. Karimi, D. Kisielewska, K.Klimaszewski, G. Korcyl, P. Kowalski, N. Krawczyk, W. Krzemień, E. Kubicz, M. Mohammed, M. Pawlik-Niedźwiecka, L. Raczyński, S. Sharma, Shivani, R. Y. Shopa, M. Skurzok, E. Stępień, W. Wiślicki, B. Zgardzińska
abstract
Research conducted in the framework of the J-PET project aims to develop a cost-effective total-body positron emission tomography scanner. As a first step on the way to construct a full-scale J-PET tomograph from long strips of plastic scintillators, a 24-strip prototype was built and tested. The prototype consists of detection modules arranged axially forming a cylindrical diagnostic chamber with an inner diameter of 360 mm and an axial field-of-view of 300 mm. Promising perspectives for a low-cost construction of a total-body PET scanner are opened due to an axial arrangement of strips of plastic scintillators, which have a small light attenuation, superior timing properties, and the possibility of cost-effective increase of the axial field-of-view. The presented prototype comprises dedicated solely digital front-end electronic circuits and a triggerless data acquisition system which required development of new calibration methods including time, thresholds and gain synchronization. The system and elaborated calibration methods including first results of the 24-module J-PET prototype are presented and discussed. The achieved coincidence resolving time equals to CRT = 490 +- 9 ps. This value can be translated to the position reconstruction accuracy s(Dl) = 18 mm which is fairly position-independent Keywords: positron emission tomography, plastic scintillators, J-PET.
Directed, elliptic and higher order flow harmonics of protons, deuterons and tritons in Au+Au collisions at sqrt(s_NN) = 2.4 GeV
J. Adamczewski-Musch, ...., G. Korcyl, ...., R. Lalik, ..., A. Malige, ...K. Nowakowski,...., W. Przygoda,...K. Pysz, ..., N. Rathod, ...,P. Salabura, .., U. Singh, J. Smyrski, et al
abstract
Flow coefficients vn of the orders n = 1 - 6 are measured with the High-Acceptance DiElectron Spectrometer (HADES) at GSI for protons, deuterons and tritons as a function of centrality, transverse momentum and rapidity in Au+Au collisions at sqrt(s_NN) = 2.4 GeV. Combining the information from the flow coefficients of all orders allows to construct for the first time, at collision energies of a few GeV, a complete, multi-differential picture of the emission pattern of these particles. The ratio v4/v22 at mid-rapidity is found to be remarkably close to the value 0.5, as might be indicative for an ideal fluid scenario.
Design, structure, microstructure and gamma radiation shielding properties of refractory concrete materials containing Ba- and Sr-doped cements
D. Madej , M. Silarski , S. Parzych
abstract
This paper presents an experimental study on the performance of shielding refractory concretes containing new types of cement for use in radiation protection technology. Three concretes with corundum aggregate and special refractory inorganic cements belonging to the CaO-Al2O3, SrO-CaO-Al2O3-ZrO2, SrO-Al2O3 and BaO-CaO-Al2O3-ZrO2 systems were tested. The products formed in the hydration of these binders were detected by SEM-EDS. The linear attenuation coefficients obtained from measurements with ? quanta emitted by the following sources: 22Na, 137Cs, 60Co, 133Ba and 152Eu in the range of 80-1408 keV were determined twice,
firstly after casting and drying (110 oC) of concretes, and secondly after sintering at 1400 oC. Especially, this work fills the gap in the literature providing the gamma rays attenuation properties of cement-containing heat resistant corundum concretes in the energy region between 779 keV and 1112 keV. The experimental setup equipped with the ORTEC GMX25P4-70 High Purity Germanium detector (HPGe) cooled with liquid nitrogen was used for the determination of the gamma-ray linear attenuation coefficients of new materials. The role of the cement on the compressive and bending strengths, pore structure (mercury intrusion porosimetry), phase
composition (XRD, FT-IR), and microstructure (SEM-EDS) of heat-treated concretes was reported. It was found that the incorporation of Sr or Ba and Zr elements with cements improved the attenuation properties of corundum-based concretes, in comparison to the concretes containing Ca. The doping alkaline earth elements i.e. Sr and Ba were chemically bonded within both hydraulic matrix of green concretes and ceramic matrix formed in concrete through sintering at 1400 ?C. Hence, these materials with gamma radiation shielding capacity are designed for special construction applications.
Status of the search for eta-mesic nuclei with particular focus on eta-Helium bound states
M. Skurzok
abstract
In this paper the search for eta-mesic nuclei with particular focus on light eta-He bound states is reviewed. A brief description of recent theoretical studies and experimental results is presented.
3D TOF-PET image reconstruction using total variation regularization
L. Raczyński, W. Wiślicki, K. Klimaszewski, W. Krzemień, P. Kopka, P. Kowalski, R. Y. Shopa, M. Bała, J. Chhokar, C. Curceanu, E. Czerwinski, K. Dulski, J. Gajewski, A. Gajos, M. Gorgol, R. Del Grande, B. Hiesmayr, B. Jasińska, K. Kacprzak, L. Kapłon, D. Kisielewska, G. Korcyl, T. Kozik, N. Krawczyk, E. Kubicz, M. Mohammed, S. Niedźwiecki, M. Pałka, M. Pawlik-Niedźwiecka, J. Raj, K. Rakoczy, A. Ruciński, S. Sharma, S. Shivani, M. Silarski, M. Skurzok, E.Ł. Stepień, B. Zgardzińska, P. Moskal
abstract
In this paper we introduce a semi-analytic algorithm for 3-dimensional image reconstruction for positron emission tomography (PET). The method consists of the back-projection of the acquired data into the most likely image voxel according to time-of-flight (TOF) information, followed by the filtering step in the image space using an iterative optimization algorithm with a total variation (TV) regularization. TV regularization in image space is more computationally efficient than usual iterative optimization methods for PET reconstruction with a full system matrix that uses TV regularization. The efficiency comes from the one-time TOF back-projection step that might also be described as a reformatting of the acquired data. An important aspect of our work concerns the evaluation of the filter operator of the linear transform mapping an original radioactive tracer distribution into the TOF back-projected image. We obtain concise, closed-form analytical formula for the filter operator. The proposed method is validated with the Monte Carlo simulations of the NEMA IEC phantom using a one-layer, 50 cm-long cylindrical device called Jagiellonian PET scanner. The results show a better image quality compared with the reference TOF maximum likelihood expectation maximization algorithm.
A simple approach for experimental characterization and validation of proton pencil beam profiles
P. Stasica, J. Baran, C. Granja, N. Krah, G. Korcyl, C. Oancea, M. Pawlik-Niedźwiecka, Sz. Niedźwiecki, M. Rydygier, A. Schavi, A. Rucinski, J. Gajewski
abstract
A precise characterization of therapeutic proton pencil beams is essential for commissioning of any treatment planning system (TPS). The dose profile characterization includes measurement of the beam lateral dose profile in the beam core and far from the beam core, in the so called low-dose envelope, and requires a sophisticated detection system with a few orders of magnitude dynamic range. We propose to use a single-quantum sensitive MINIPIX TIMEPIX detector, along with an in-house designed holder to perform measurements of the pencil beam dose profile in air and in water. We validated the manufacturer calibration of the MINIPIX TIMEPIX detector in proton beams of various energies and compared the deposited energy spectra to Monte Carlo (MC) simulations. The precision of the lateral dose profile measurements has been systematically validated against Krakow proton facility commissioning data and dose profile simulations performed with MC codes GATE/Geant4 and FRED. We obtained an excellent agreement between MINIPIX TIMEPIX measurements and simulations demonstrating the feasibility of the system for a simple characterization and validation of proton pencil beams. The proposed approach can be implemented at any proton therapy facility to acquire experimental data needed to commission and validate analytical and MC based TPS.
Search for the eta mesic 3He in the pd->dppi0 reaction with the WASA-at-COSY facility
P. Adlarson, ..., E. Czerwiński, A. Khreptak, W. Krzemień, P. Moskal, O. Rundel, I. Schätti-Ozerianska, M. Skurzok, M.J. Zieliński, et al.
abstract
The excitation function for the pd -> dppi0 reaction has been measured by WASA-at-COSY experiment with the aim of searching for 3He-eta mesic nuclei. The measurement in the vicinity of eta meson production was performed using a ramped proton beam. The data analysis and interpretation was carried out with the assumption that the eta-mesic Helium decays via the formation of an intermediate N*(1535) resonance. No direct signal of the eta-mesic nucleus is observed in the excitation function. We determine a new improved upper limit for the total cross section for the bound state production and decay in the pd -> (3He-eta)bound -> dppi0 process. It varies between 13 nb to 24 nb for the bound state with width in the range Gamma (5,50) MeV.
Characterization of the SIDDHARTA-2 luminosity monitor
M. Skurzok, A. Scordo, S. Niedzwiecki, A. Baniahmad, M. Bazzi, D. Bosnar, M. Bragadireanu, M. Carminati, M. Cargnelli, A. Clozza, C. Curceanu, L. De Paolis, R. Del Grande, L. Fabbietti, C. Fiorini, C. Guaraldo, M. Iliescu, M. Iwasaki, P. Levi Sandri, J. Marton, M. Miliucci, P. Moskal, K. Piscicchia, F. Sgaramella, H. Shi, M. Silarski, D. L. Sirghi, F. Sirghi, A. Spallone, M. Tüchler, O. Vazquez Doce, J. Zmeskal
abstract
A luminosity monitor, based on plastic scintillator detectors, has been developed for the SIDDHARTA-2 experiment aiming to perform high precision measurements of kaonic atoms and was installed in 2020 on the DAFNE e+e- collider at LNF (Laboratori Nazionali di Frascati, INFN). The main goal of this system is to provide the~instantaneous and integrated luminosity of the DAFNE facility by measuring the rate of K+K- correlated pairs emitted by the Phi meson decay. This task requires an accurate timing of the DAQ signals, as well as timing resolution below 1ns, in order to disentangle the K+- signals from the background minimum ionizing particles (MIPs) produced during the e+e- collisions at DAFNE. In this paper the luminosity monitor concept as well as its laboratory characterization and the first results inside DAFNE are presented.
Upper limit on the eta->pi+pi- branching fraction with the KLOE experiment
D. Babusci, M. Berlowski, C. Bloise, F. Bossi, P. Branchini, A. Budano, B. Cao, F. Ceradini, P. Ciambrone, F. Curciarello, E. Czerwiński, G. D'Agostini, E. Dan?, V. De Leo, E. De Lucia, A. De Santis, P. De Simone, A. Di Cicco, A. Di Domenico, D. Domenici, A. D'Uffizi, A. Fantini, P. Fermani, S. Fiore, A. Gajos, P. Gauzzi, S. Giovannella, E. Graziani, V. L. Ivanov, T. Johansson, X. Kang, D. Kisielewska-Kamińska, E. A. Kozyrev, W. Krzemien, A. Kupsc, P. A. Lukin, G. Mandaglio, M. Martini, R. Messi, S. Miscetti, D. Moricciani, P. Moskal, S. Parzych, A. Passeri, V. Patera, E. Perez del Rio, P. Santangelo, M. Schioppa, A. Selce, M. Silarski, F. Sirghi, E. P. Solodov, L. Tortora, G. Venanzoni, W. Wiślicki, M. Wolke
abstract
Based on an integrated luminosity of 1.61 fb^{-1} e+e- collision data collected with the KLOE detector at DAFNE, the Frascati phi-factory, a search for the P- and CP-violating decay eta->pi+pi- has been performed. Radiative phi->eta gamma decay is exploited to access the eta mesons. No signal is observed in the pi+pi- invariant mass spectrum, and the upper limit on the branching fraction at 90% confidence level is determined to be B(eta->pi+pi-)<4.9x10^{-6}, which is approximately three times smaller than the previous KLOE result. From the combination of these two measurements we get B(eta->pi+pi-)<4.4x10^{-6} at 90% confidence level.
Sensitivity of discrete symmetry tests in the positronium system with the J-PET detector
A. Gajos
abstract
Study of certain angular correlations in the three-photon annihilations of the triplet state of positronium, the electron?positron bound state, may be used as a probe of potential CP and CPT-violating effects in the leptonic sector. We present the perspectives of CP and CPT tests using this process recorded with a novel detection system for photons in the positron annihilation energy range, the Jagiellonian Positron Emission Tomography (J-PET). We demonstrate the capability of this system to register three-photon annihilations with an unprecedented range of kinematical configurations and to measure the CPT-odd correlation between positronium spin and annihilation plane orientation with a precision improved by at least an order of magnitude with respect to present results. We also discuss the means to control and reduce detector asymmetries in order to allow J-PET to set the first measurement of the correlation between positronium spin and momentum of the most energetic annihilation photon which has never been studied to date.
Prospects and clinical perspectives of total-body PET imaging using plastic scintillators
P. Moskal, E. Ł. Stępień
abstract
Total-body PET opens new diagnostic paradigm with prospects for personalized disease treatment, yet the high cost of the current crystal-based PET technology limits dissemination of total-body PET in hospitals and even in the research
clinics.
The J-PET tomography system is based on axially arranged low-cost plastic scintillator strips. It constitutes a realistic cost-effective solution of a total-body PET for broad clinical applications.
High sensitivity of total-body J-PET and trigger-less data acquisition enable multi-photon imaging, opening possibilities for multi-tracer and positronium imaging, thus promising quantitative enhancement of specificity in cancer and inflammatory diseases assessment.
An example of dual tracer analysis, becoming possible with total-body J-PET system, could be a concurrent application of FDA-approved 82Rb-Chloride and [18F]FDG, allowing simultaneous assessment of myocardium metabolic rate and perfusion of the cardiovascular system.
Technical Attenuation Length Measurement of Plastic Scintillator Strips for the Total-Body J-PET Scanner
Ł. Kapłon
abstract
The aim of the performed technical attenuation length measurement is to compare light attenuation of a few commercially available plastic scintillator strips and to select the best scintillator type for the total-body Jagiellonian Positron Emission Tomograph (J-PET) construction. Few models of plastic scintillators obtained from different manufacturers were tested. All strips had the same rectangular cross section and dimensions 6 mm x 24 mm x 1000 mm with all surfaces polished. The light attenuation length was measured by exciting the scintillator strip at different positions with an ultraviolet lamp emitting at 365 nm and reading light signal collected at one side of the strip by a silicon photodiode. Among measured plastic scintillators, EJ-200 possesses the highest technical light attenuation length and is suitable for construction of total-body J-PET scanner.
X-ray microtomography as a new approach for imaging and analysis of tumor spheroids
H. Karimi, B. Leszczyński, T. Kołodziej, E. Kubicz, M. Przybyło, E. Stępień
abstract
Three-dimensional (3D) spheroids mimic important properties of tumors and may soon become a reasonable
substitute for animal models and human tissue, eliminating numerous problems related to in vivo and ex vivo
experiments and pre-clinical drug trials. Currently, various imaging methods including X-ray microtomography
(micro-CT), exist but their spatial resolution is limited. Here, we visualized and provided a morphological
analysis of spheroid cell cultures using micro-CT and compared it to that of confocal microscopy. An approach is
proposed that can potentially open new diagnostic opportunities to determine the morphology of cancer cells
cultured in 3D structures instead of using actual tumors.
Spheroids were formed from human melanoma cell lines WM266-4 and WM115 seeded at different cell
densities using the hanging drop method. Micro-CT analysis of spheroid showed that spheroid size and shape
differed depending on the cell line, initial cell number, and duration of culture.
The melanoma cell lines used in this study can successfully be cultured as 3D spheroids and used to substitute
human and animal models in pre-clinical studies. The micro-CT allows for high-resolution visualization of the
spheroids structure.
Total branching ratio of the K- two-nucleon absorption in 12C
R. Del Grande, K. Piscicchia, M. Cargnelli, C. Curceanu, L. Fabbietti, J. Marton, P. Moskal, A. Ramos, A. Scordo, D. Sirghi, M. Skurzok, O.Vazquez Doce, S. Wycech, J. Zmeskal, V. De Leo, G. Mandaglio, M. Martini, E.Perez Del Rio, A. Selce, M. Silarski
abstract
This work is a critical re-analysis of the results obtained by the AMADEUS collaboration, concerning the measurement of the K? multi-nucleon absorption reactions, on a 12C target, in the Lambdap final state (Del Grande et al 2019 Eur. Phys. J. C 79, 190). We show that a good estimate of the K- two-nucleon absorption total branching ratio can be extracted, given that the measured final state interactions and conversion reactions contain information on almost all the remaining hyperon-nucleon final state combinations. The main contribution to the total branching ratio of the K? two-nucleon absorption in Carbon is extracted from the measured ratios and is found to be (16.1+-2.9(stat.)-5.5+4.3(syst.))%, which is in agreement with recent theoretical predictions. The missing contribution, from those few channels for which a Lambdap pair could not be detected in the final state of the interaction, is also estimated combining both the measured branching ratios and the available theoretical information, and amounts to (5.5+-0.1(stat.)-0.9+1.0(syst.))%. All together the total branching ratio of the K- two-nucleon absorption in Carbon is found to be (21.6+-2.9(stat.)-5.6+4.4(syst.))%.
Differential Cross Sections for Neutron-Proton Scattering in the Region of the d*(2380) Dibaryon Resonance
P. Adlarson, ..., E. Czerwiński, A. Khreptak, W. Krzemień, P. Moskal, O. Rundel, I. Schätti-Ozerianska, M. Skurzok, M.J. Zieliński, et al.
abstract
Differential cross-sections have been extracted from exclusive and kinematically complete high-statistics measurements of quasifree polarized np scattering performed in the energy region of the d*(2380) dibaryon resonance covering the range of beam energies Tn=0.98?1.29 GeV (s=2.32?2.44 GeV). The experiment was carried out with the WASA-at-COSY setup having a polarized deuteron beam impinged on the hydrogen pellet target and utilizing the quasifree process dp->np + p_spectator. In this way, the np differential cross-section sigma(theta) was measured over a large angular range. The obtained angular distributions complement the corresponding analyzing power Ay(theta) measurements published previously. A SAID partial-wave analysis incorporating the new data strengthens the finding of a resonance pole in the coupled D33-G33 waves
Feasibility studies for the measurement of time-like proton electromagnetic form factors from pp->m+m- at PANDA at FAIR
G. Barucca, ..., G. Korcyl, P. Moskal et al.
abstract
This paper reports on Monte Carlo simulation results for future measurements of time-like proton electromagnetic form factors, |GE| and |GM|, using the pp?m+m- reaction at PANDA (FAIR). The electromagnetic form factors are fundamental quantities parameterizing the electric and magnetic structure of hadrons. This work estimates the statistical and total accuracy with which the form factors can be measured at PANDA, using an analysis of simulated data within the PandaRoot software framework. The most crucial background channel is pp->pi+pi-, due to the very similar behavior of muons and pions in the detector. The suppression factors are evaluated for this and all other relevant background channels at different values of antiproton beam momentum. The signal/background separation is based on a multivariate analysis, using the Boosted Decision Trees method. An expected background subtraction is included in this study, based on realistic angular distributions of the background contribution. Systematic uncertainties are considered and the relative total uncertainties of the form factor measurements are presented.
State of the art in total body PET
S. Vandenberghe, P. Moskal and J.S. Karp
abstract
The idea of a very sensitive positron emission tomography (PET) system covering a large portion of the body of a patient already dates back to the early 1990s. In the period 2000-2010, only some prototypes with long axial field of view (FOV) have been built, which never resulted in systems used for clinical research. One of the reasons was the limitations in the available detector technology, which did not yet have sufficient energy resolution, timing resolution or countrate capabilities for fully exploiting the benefits of a long axial FOV design. PET was also not yet as widespread as it is today: the growth in oncology, which has become the major application of PET, appeared only after the introduction of PET-CT (early 2000).The detector technology used in most clinical PET systems today has a combination of good energy and timing resolution with higher countrate capabilities and has now been used since more than a decade to build time-of-flight (TOF) PET systems with fully 3D acquisitions. Based on this technology, one can construct total body PET systems and the remaining challenges (data handling, fast image reconstruction, detector cooling) are mostly related to engineering. The direct benefits of long axial FOV systems are mostly related to the higher sensitivity. For single organ imaging, the gain is close to the point source sensitivity which increases linearly with the axial length until it is limited by solid angle and attenuation of the body. The gains for single organ (compared to a fully 3D PET 20-cm axial FOV) are limited to a factor 3-4. But for long objects (like body scans), it increases quadratically with scanner length and factors of 10?40 × higher sensitivity are predicted for the long axial FOV scanner. This application of PET has seen a major increase (mostly in oncology) during the last 2 decades and is now the main type of study in a PET centre. As the technology is available and the full body concept also seems to match with existing applications, the old concept of a total body PET scanner is seeing a clear revival. Several research groups are working on this concept and after showing the potential via extensive simulations; construction of these systems has started about 2 years ago. In the first phase, two PET systems with long axial FOV suitable for large animal imaging were constructed to explore the potential in more experimental settings. Recently, the first completed total body PET systems for human use, a 70-cm-long system, called PennPET Explorer, and a 2-m-long system, called uExplorer, have become reality and first clinical studies have been shown. These results illustrate the large potential of this concept with regard to low-dose imaging, faster scanning, whole-body dynamic imaging and follow-up of tracers over longer periods. This large range of possible technical improvements seems to have the potential to change the current clinical routine and to expand the number of clinical applications of molecular imaging. The J-PET prototype is a prototype system with a long axial FOV built from axially arranged plastic scintillator strips.This paper gives an overview of the recent technical developments with regard to PET scanners with a long axial FOV covering at least the majority of the body (so called total body PET systems). After explaining the benefits and challenges of total body PET systems, the different total body PET system designs proposed for large animal and clinical imaging are described in detail. The axial length is one of the major factors determining the total cost of the system, but there are also other options in detector technology, design and processing for reducing the cost these systems. The limitations and advantages of different designs for research and clinical use are discussed taking into account potential applications and the increased cost of these systems.
Performance assessment of the 2gamma positronium imaging with the total-body PET scanners
P. Moskal, D. Kisielewska, Z. Bura, C. Chhokar, C. Curceanu, E. Czerwiński, M. Dadgar, K. Dulski, J. Gajewski, A. Gajos, M. Gorgol, R. Del Grande, B. C. Hiesmayr, B. Jasińska, K. Kacprzak, A. Kamińska, Ł. Kapłon, H. Karimi, G. Korcyl, P. Kowalski, N. Krawczyk, W. Krzemień, T. Kozik, E. Kubicz, P. Małczak, M. Mohammed, Sz. Niedźwiecki, M. Pałka, M. Pawlik-Niedźwiecka, M. Pędziwiatr, L. Raczyński, J. Raj, A. Ruciński, S. Sharma, Shivani, R. Y. Shopa, M. Silarski, M. Skurzok, E. Ł. Stępień, S. Vandenberghe, W. Wiślicki, B. Zgardzińska
abstract
In living organisms the positron-electron annihilation (occurring during the PET imaging) proceeds in about 30% via creation of a metastable ortho-positronium atom. In the tissue, due to the pick-off and conversion processes, over 98% of ortho-positronia annihilate into two 511~keV photons. In this article we assess the feasibility for reconstruction of the mean ortho-positronium lifetime image based on annihilations into two photons. The main objectives of this work include: (i) estimation of the sensitivity of the total-body PET scanners for the ortho-positronium mean lifetime imaging using 2gamma annihilations, and (ii) estimation of the spatial and time resolution of the ortho-positronium image as a function of the coincidence resolving time (CRT) of the scanner. Simulations are conducted assuming that radiopharmaceutical is labelled with 44Sc isotope emitting one positron and one prompt gamma. The image is reconstructed on the basis of triple coincidence events. The ortho-positronium lifetime spectrum is determined for each voxel of the image. Calculations were performed for cases of total-body detectors build of (i) LYSO scintillators as used in the EXPLORER PET, and (ii) plastic scintillators as anticipated for the cost-effective total-body J-PET scanner. To assess the spatial and time resolution the three cases were considered assuming that CRT is equal to 140ps, 50ps and 10ps. The estimated total-body PET sensitivity for the registration and selection of image forming triple coincidences is larger by a factor of 12.2 (for LYSO PET) and by factor of 4.7 (for plastic PET) with respect to the sensitivity for the standard 2gamma imaging by LYSO PET scanners with AFOV=20cm.
Estimating relationship between the Time Over Threshold and energy loss by photons in plastic scintillators used in the J-PET scanner
S. Sharma, J. Chhokar, C. Curceanu, E. Czerwinski, M. Dadgar, K. Dulski, J. Gajewski, A. Gajos, M. Gorgol, N. Gupta-Sharma, R. Del Grande, B. C. Hiesmayr, B. Jasinska, K. Kacprzak, L. Kaplon, H. Karimi, D. Kisielewska, K. Klimaszewski, G. Korcyl, P. Kowalski, T. Kozik, N. Krawczyk, W. Krzemien, E. Kubicz, M. Mohammed, Sz. Niedzwiecki, M. Palka, M. Pawlik-Niedzwiecka, L. Raczynski, J. Raj, A. Rucinski, Shivani, R. Y. Shopa, M. Silarski, M. Skurzok, E. L. Stepien, W. Wislicki, B. Zgardzinska, P. Moskal
abstract
Time-Over-Threshold (TOT) technique is being used widely due to its implications in developing the multi channel readouts mainly when fast signal processing is required. Using TOT technique as a measure of energy loss instead of charge integration methods significantly reduces the signals readout cost by combining the time and energy information. Therefore, this approach can potentially be used in J-PET tomograph which is build from plastic scintillators characterized by fast light signals. The drawback in adopting this technique is lying in the non-linear correlation between input energy loss and TOT of the signal. The main motivation behind this work is to develop the relationship between TOT and energy loss and validate it with the J-PET tomograph.
The experiment was performed using the 22Na beta emitter source placed in the center of the J-PET tomograph. One can obtain primary photons of two different energies: 511 keV photon from the annihilation of positron (direct annihilation or through the formation of para-Positronim atom or pick-off process of ortho-Positronium atoms), and 1275 keV prompt photon. This allows to study the correlation between TOT values and energy loss for energy range up to 1000 keV. As the photon interacts dominantly via Compton scattering inside the plastic scintillator, there is no direct information of primary photon energy. However, using the J-PET geometry one can measure the scattering angle of the interacting photon. Since, 22Na source emits photons of two different energies, it is required to know unambiguously the energy of incident photons and its corresponding scattering angle for the estimation of energy deposition. In this work, the relationship between Time Over Threshold and energy loss by interacting photons inside the plastic scintillators used in J-PET scanner is established for a energy deposited range 100-1000 keV.
Hit-time and hit-position reconstruction in strips of plastic scintillators using multi-threshold readouts
N. G. Sharma, M. Silarski, J. Chhokar, E. Czerwinski, C. Curceanu, K. Dulski, K. Farbaniec, A. Gajos, R. Del Grande, M. Gorgol, B. C. Hiesmayr, B. Jasinska, K. Kacprzak, L. Kaplon, D. Kisielewska, K. Klimaszewski, G. Korcyl, P. Kowalski, N. Krawczyk, W. Krzemien, T. Kozik, E. Kubicz, M. Mohammed, Sz. Niedzwiecki, M. Palka, M. Pawlik-Niedzwiecka, L. Raczynski, J. Raj, S. Sharma, S. Shivani, R. Y. Shopa, M. Skurzok, W. Wislicki, B. Zgardzinska, P. Moskal
abstract
In this article a new method for the reconstruction of hit-position and hit-time of photons in long scintillator detectors is investigated. This research is motivated by the recent development of the positron emission tomography scanners based on plastic scintillators. The proposed method constitutes a new way of signal processing in Multi-Voltage-Technique. It is based on the determination of the degree of similarity between the registered signals and the synchronized model signals stored in a library. The library was established for a set of well defined hit-positions along the length of the scintillator. The Mahalanobis distance was used as a measure of similarity between the two compared signals. The method was validated on the experimental data measured using two-strips J-PET prototype with dimensions of 5x9x300 mm. The obtained Time-of-Flight (TOF) and spatial resolutions amount to 325 ps (FWHM) and 25 mm (FWHM), respectively. The TOF resolution was also compared to the results of an analogous study done using Linear Fitting method. The best TOF resolution was obtained with this method at four pre-defined threshold levels which was comparable to the resolution achieved from the Mahalanobis distance at two pre-defined threshold levels. Although the algorithm of Linear Fitting method is much simpler to apply than the Mahalanobis method, the application of the Mahalanobis distance requires a lower number of applied threshold levels and, hence, decreases the costs of electronics used in PET scanner.
J-PET Framework: Software platform for PET tomography data reconstruction and analysis
W. Krzemień, A. Gajos, K. Kacprzak, K. Rakoczy, G. Korcyl
abstract
J-PET Framework is an open-source software platform for data analysis, written in C++ and based on the ROOT package. It provides a common environment for implementation of reconstruction, calibration and filtering procedures, as well as for user-level analyses of Positron Emission Tomography data. The library contains a set of building blocks that can be combined by users with even little programming experience, into chains of processing tasks through a convenient, simple and well-documented API. The generic input-output interface allows processing the data from various sources: low-level data from the tomography acquisition system or from diagnostic setups such as digital oscilloscopes, as well as high-level tomography structures e.g. sinograms or a list of lines-of-response. Moreover, the environment can be interfaced with Monte Carlo simulation packages such as GEANT and GATE, which are commonly used in the medical scientific community.
Three-nucleon dynamics in dp breakup collisions using the WASA detector at COSY-Jülich
P. Adlarson, ..., E. Czerwiński, A. Khreptak, W. Krzemień, P. Moskal, M. Skurzok, M.J. Zieliński, et al.
abstract
The differential cross section for the 1 H (d, pp)n breakup reaction at deuteron beam energy of 340 MeV
has been measured with the use of the WASA detector at COSY-Jülich. The set of proton-proton coincidences
registered at the Forward Detector has been analyzed on a dense grid of kinematic variables, giving in total
around 5600 data points. The cross-section data are compared to theoretical predictions based on the state-of-
the-art nucleon-nucleon potentials, combined with a three-nucleon force or the Coulomb interaction or carried
out in a relativistic regime.
The cosmological constant and Higgs mass with emergent gauge symmetries
S.D. Bass, J. Krzysiak
abstract
We discuss the Higgs mass and cosmological constant in the context of an emergent Standard Model, where the gauge symmetries dissolve in the extreme ultraviolet. In this scenario the cosmological constant scale is suppressed by power of the large scale of emergence and expected to be of similar size to neutrino masses. Cosmology constraints then give an anthropic upper bound on the Higgs mass.
Kaonic Atoms to Investigate Global Symmetry Breaking
C. Curceanu, C. Guaraldo, D. Sirghi, A. Amirkhani, A Baniahmad, M. Bazzi, G. Bellotti, D. Bosnar, A. M. Bragadireanu, M. Cargnelli, M. Carminati, A. Clozza, L. De Paolis, R. Del Grande, C. Fiorini, M. Iliescu, M. Iwasaki, P. King, P. Levi Sandri, J. Marton, M. Miliucci, P. Moskal, S. Niedzwiecki, S. Okada, K. Piscicchia, A. Scordo, M. Silarski, F. Sirghi, M. Skurzok, A. Spallone, M. Tuechler, G. Utica, O. Vazquez Doce, J. Zmeskal
abstract
Kaonic atoms measure the antikaon-nucleus interaction at almost zero relative energy, allowing one to determine basic low-energy quantum chromodynamics (QCD) quantities, namely, the antikaon-nucleon ( K- N) scattering lengths. The latter are important for extracting the sigma terms which are built on the symmetry breaking part of the Hamiltonian, thereby providing a measure of chiral and SU(3) symmetries breaking. After discussing the sigma terms and their relations to the kaonic atoms, we describe the most precise measurement in the literature of kaonic hydrogen, performed at LNF-INFN by the SIDDHARTA experiment. Kaonic deuterium is still to be measured, and two experiments are planned. The first, SIDDHARTA-2 at LNF-INFN was installed on DAFNE in spring 2019 and will collect data in 2020. The second, E57 at J-PARC, will become operative in 2021
The cylindrical-GEM inner tracker detector of the KLOE-2 experiment
G.Bencivenni, ..., E. Czerwiński, et al.
abstract
A new tracking device, the Inner Tracker, was installed at the interaction region of KLOE-2 and it was operated together with the Drift Chamber to improve track and vertex reconstruction capabilities of the new experimental apparatus. The Inner Tracker is a four-layer cylindrical triple-GEM detector with each layer equipped with an X-V strips-pads stereo readout. Although GEM detectors have been extensively used in high energy physics experiments, the IT, with its fully-cylindrical geometry is a frontier detector and KLOE-2 is the first experiment which benefited of this novel detector technology operated at a collider.
The operation of the Inner Tracker will be presented, together with the results of the alignment and calibration and tracking?vertexing performance of such a unique detector.
Study of the N* momentum distribution for experimental eta-mesic 3He searches
N. G. Kelkar, D. Bedoya Fierro, H. Kamada, M. Skurzok
abstract
The proximity of the etaN threshold to the mass of the N*(1535) allows us to consider the eta-nucleus interaction below the eta threshold as a series of excitations, decays of the N* on the constituent nucleons and the eventual decay of the N* to a nucleon and a pion. Experimental searches for eta-mesic nuclei rely on this model in their analysis of data where an eta-mesic nucleus could have been formed. However, the momentum distribution of an N* is often approximated to be the same as that of a nucleon inside the nucleus. Our aim is to obtain an estimate of the error introduced by this assumption and hence we calculate the momentum distribution of the N* formed inside 3He. This distribution is found to be narrower than that of a nucleon inside 3He. The latter affects the outgoing particles kinematics and reduces the determined acceptance of their experimental registration by the detection setup. This reduction is crucial for the determination of cross sections in the search for eta-mesic helium.
Towards Lattice Quantum Chromodynamics on FPGA devices
G. Korcyl, P. Korcyl
abstract
In this paper we describe a single-node, double precision Field Programmable Gate Array (FPGA) implementation of the Conjugate Gradient algorithm in the context of Lattice Quantum Chromodynamics. As a benchmark of our proposal we invert numerically the Dirac-Wilson operator on a 4-dimensional grid on three Xilinx hardware solutions: Zynq Ultrascale+ evaluation board, the Alveo U250 accelerator and the largest device available on the market, the VU13P device. In our implementation we separate software/hardware parts in such a way that the entire multiplication by the Dirac operator is performed in hardware, and the rest of the algorithm runs on the host. We find out that the FPGA implementation can offer a performance comparable with that obtained using current CPU or Intel?s many core Xeon Phi accelerators. A possible multiple node FPGA-based system is discussed and we argue that power-efficient High Performance Computing (HPC) systems can be implemented using FPGA devices only.
Measurement of the branching fraction for the decay KS -> pi mu nu with the KLOE detector
D. Babusci, M. Berlowski, C. Bloise, F. Bossi, P. Branchini, A. Budano, B. Cao, F. Ceradini, P. Ciambrone, F. Curciarello, E. Czerwisnski, G. D'Agostini, E. Dane, V. De Leo, E. De Lucia, A. De Santis, P. De Simone, A. Di Cicco, A. Di Domenico, D. Domenici, A. D'Uffizi, A. Fantini, P. Fermani, S. Fiore, A. Gajos, P. Gauzzi, S. Giovannella, E. Graziani, V. L. Ivanov, T. Johansson, X. Kang, D. Kisielewska-Kamisnska, E. A. Kozyrev, W. Krzemien, A. Kupsc, P. A. Lukin, G. Mandaglio, M. Martini, R. Messi, S. Miscetti, D. Moricciani, P. Moskal, S. Parzych, A. Passeri, V. Patera, E. Perez del Rio, P. Santangelo, M. Schioppa, A. Selce, M. Silarski, F. Sirghi, E. P. Solodov, L. Tortora, G. Venanzoni, W. Wislicki, M. Wolke
abstract
Based on a sample of 300 million KS mesons produced in phi -> KLKS decays recorded by the KLOE experiment at the DAFNE e+e- collider we have measured the branching fraction for the decay KS -> pi mu nu. The KS mesons are identified by the interaction of KL mesons in the detector. The KS -> pi mu nu decays are selected by a boosted decision tree built with kinematic variables and by a time-of-flight measurement. Signal efficiencies are evaluated with data control samples of KL -> pi mu nu decays. A fit to the reconstructed muon mass distribution finds 7223?180 signal events. Normalising to the KS -> pi+ pi- decay events the result for the branching fraction is B(KS -> pi mu nu) = (4.56+-0.11stat+-0.17syst)×10-4.
Studies of Ortho-Positronium Decays into Three Photons with the J-PET Detector
A. Gajos on behalf of the J-PET collaboration
abstract
The Jagiellonian Positron Emission Tomograph (J-PET) setup, besides being the first PET scanner built with plastic scintillators is currently used to conduct a broad range of experiments involving ortho-positronium (o-Ps) decays into three photons. We present results of studies of o-Ps->3g decays performed in J-PET with a view to search for angular correlations between the photons' momenta and positronium spin direction which would violate the combined CPT symmetry, scarcely tested in leptonic systems. To date, the most precise CPT test using ortho-positronium decays reached the precision of 3×10-3 whereas effects limiting the sensitivity are only expected at the level of 10-9. In the discussed J-PET measurement, ortho-positronium atoms are created by positrons from a 22Na source thermalizing in an extensive-size cylindrical target of mesoporous silica and decay positions are reconstructed using a trilateration-based technique. Decay photons are recorded by 192 strips of plastic scintillators with high timing resolution. Such a setup allows for registration of an unprecedented spectrum of geometrical configurations of o-Ps->3g decays including also correlations with positronium spin. With an angular resolution and o-Ps polarization control improved with respect to previous measurements, J-PET aims at achieving the sensitivity of CPT test at a precision level of at least 10-4.
Synthesis and Characterization of Plastic Scintillators for the Total-body J-PET Scanner
Ł. Kapłon
abstract
The aim of the research was to develop polystyrene scintillator for use in the novel time-of-flight Jagiellonian Positron Emission Tomography (J-PET) scanner being elaborated for the whole-body imaging. To achieve this goal, polystyrene based plastic scintillators with the different chemical compositions were produced and characterized. Light output, decay time and emission spectra were measured to develop best composition of polystyrene scintillator.
Simulation of Positronium Decays in View of Charge Conjugation Symmetry Test with the J-PET Detector
J. Chhokar on behalf of the J-PET Collaboration
abstract
We present search of the C-forbidden decays of positronium with the J-PET detector. J-PET is a first
tomograph based on plastic scintillators and, due to large acceptance and high angular resolution, it is suitable for
studies of various phenomena such as: discrete symmetries in decays of positronium atom or entangled states of
photons as well as the medical imaging. In view of the C-symmetry test, the J-PET is used inter alia to determine
the angular distribution of the three annihilation photons from positronium decay.
Development of J-PEM for Breast Cancer Detection
Shivani, E. Łuczynska, S. Heinze and P. Moskal
abstract
A detection system of the conventional PET tomograph is set-up to record data from e+e- annihilation
into two photons, each with energy of 511 keV, and to give information about the spatial density distribution of
a radiopharmaceutical in the patients body. Dedicated positron emission mammography (PEM) systems provide
a potentially high sensitivity, high-resolution, low attenuation, and lower cost alternative to whole body PET.
We have designed, built, and performed initial evaluation of a large field-of-view Jagiellonian Positron Emission
Mammography (J-PEM) system. This 3D system is based on novel idea of applying plastic scintillators to detect
annihilation photons and improving spatial resolution by utilization of wavelength shifters (WLS). In addition,
this device is being developed in view of classification of malignancy based on the possibility of positronium mean
lifetime imaging. Here we present the first results from the simulations as motivation for our investigation.
J-PET Monte Carlo Simulations for Time-Reversal Symmetry Test in Ortho-Positronium Decay
J. Raj, D. Kisielewska and E. Czerwiński
abstract
This article reports the development of Monte Carlo simulations of the J-PET detector using the Geant4 toolkit
aimed at serving as a foundation for testing the time-reversal symmetry in the decay of ortho-Positronium (o-Ps)
atoms. In order to observe asymmetries in time-reversal, it is important to understand the physical proper-
ties of the signal candidates (o-Ps->3g) recorded by the detector setup. The simulations aim at replicating
the experimental procedure of producing meta-stable triplet states of positronium and testing the T-symmetry
using symmetry-odd operators with the Jagiellonian-Positron Emission Tomograph (J-PET) detector.
TOT Method for the Disentanglement of Photons in Positron Annihilation Lifetime Spectroscopy
S. Sharma on behalf of J-PET collaboration
abstract
The Jagiellonian Positron Emission Tomograph (J-PET) is a multidisciplinary device aiming to perform studies in medical field as well as to test the fundamental symmetries. The plastic scintillators offer very good time resolution. Although, due to the low atomic number of the plastic material, the incident photons interact mainly via the Compton effect. Thus instead of full energy deposition by the photon, there is a range of energy depositions depending on its scattering angle. For the positron annihilation lifetime spectroscopy studies, it is necessary to distinguish the photons emitted from different processes. Therefore, it becomes crucial to find a method to disentangle the photons of different energies. In the present work, the control spectra are discussed which can unambiguously categorize the photons of different energies and origins, which are essential for the studies based on the positronium lifetime
Experimental and theoretical L-shell ionization cross sections of heavy atoms by impact of Si ions
M.Oswal,Sunil Kumar,U. Singh,Shashank Singh, G.Singh, K.P.Singh, D.Mehta, A.M.P.Mendez, D.M.Mitnik, C.C.Montanari, D.Mitra, T.Nandi
abstract
We present a theoretical and experimental study of the subshell resolved L-shell ionization of relativistic targets such as 73Ta, 78Pt, 90Th, and 92U. The measurements of x-ray production cross sections by (84?140 MeV) Si+q ions (q = 8; 12), were held at the Inter-University Accelerator Centre of New Delhi. Multiple-hole fluorescence and Coster-Kronig yields were used to obtain the Li(i = 1?3) ionization cross sections from the measured x-ray production cross sections of L?, L?, and L?, L?, and L? lines. The experimental results are compared with ab initio theoretical calculations by means of the shell-wise local plasma approximation (SLPA). This model uses the quantum dielectric formalism to obtain the total ionization cross sections from an initial ground state. The wave functions and binding energies of the different targets were obtained by solving the fully relativistic Dirac equation using the HULLAC code package. These calculations are based on first order perturbation theory with a central field, including Breit interaction and quantum electrodynamics corrections. The present SLPA ionization cross sections of the L-shell are found to be independent of the charge state of the Si ions. The experimental observations display also quite similar character if the correct mean projectile charge state inside the target is used for including the multiple ionization effect during ion-solid collisions. A general good agreement between the experimental measurements and full theoretical calculations supports the reliability of present results. The comparison also includes the well-known ECPSSR and ECUSAR semi empirical approximations. We noted that the ECUSAR results agree well with the SLPA, while the ECPSSR cross sections are rather low
PALS Avalanche - A New PAL Spectra Analysis Software
K. Dulski
abstract
A novel concept for tomography of the human body developed by the Jagiellonian Positronium EmissionTomography (J-PET) project provides the possibility to combine metabolic information collected by standardPET with structural information obtained from positronium lifetime. This results in a morphometric image. Tothis end, there is a need to develop software compatible with the J-PET Framework for fast online analysis duringimaging. PALS Avalanche is a software developed on UNIX system and based on ROOT software, which allows oneto decompose positronium annihilation lifetime spectra in the form of a set of single time differences and histogram.Performance of the PALS Avalanche will be tested by analysing simulated PAL spectra.
Search for eta mesic 3He with the WASA-at-COSY facility in the pd-> 3He 2gamma and pd-> 3He 6gamma reactions
P. Adlarson, ..., E. Czerwiński, O. Khreptak, W. Krzemień, P. Moskal, O. Rundel, I. Schätti-Ozerianska, M. Skurzok, M.J. Zieliński, et al.
abstract
We report on the experimental search for the bound state of an eta meson and 3He nucleus performed using the WASA-at-COSY detector setup. In order to search for the eta-mesic nucleus decay, the pd->3He2gamma and pd->3He6gamma channels have been analysed. These reactions manifest the direct decay of eta meson bound in 3He nucleus. This non-mesonic decay channel has been considered for the first time. When taking into account only statistical errors, the obtained excitation functions reveal a slight indication for a possible bound state signal corresponding to an 3He-eta nucleus width Gamma above 20 MeV and binding energy Bs between 0 and 15 MeV. However, the determined cross sections are consistent with zero in the range of the systematic uncertainty. Therefore, as final result we estimate only the upper limit for the cross section of the eta-mesic 3He nucleus formation followed by the eta meson decay which varies between 2 nb and 15 nb depending on possible bound state parameters.
Emergent Gauge Symmetries and Particle Physics
S.D. Bass
abstract
Hadron properties and interactions are emergent from QCD. Atomic and condensed matter physics are emergent from QED. Could the local gauge symmetries of particle physics also be emergent? We give an introduction to this question and recent ideas connecting it to the (meta)stability of the Standard Model Higgs vacuum. With an emergent Standard Model the gauge symmetries would dissolve in the ultraviolet. This scenario differs from unification models which exhibit maximum symmetry in the extreme ultraviolet. With emergence, new global symmetry violations would appear in higher dimensional operators.
Studies of the ortho-Positronium lifetime for cancer diagnostics
Z. Bura, K. Dulski, E. Kubicz, P. Małczak, M. Pędziwiatr, M. Szczepanek, E.Ł. Stępień, P. Moskal
abstract
Positron Annihilation Lifetime Spectroscopy (PALS) is a technique based on the analysis of the lifetime of positronium emitted from implanted or delivered positronium donors. This technique employs the lifetime and intensity dependence on the structure of analyzed material. Due to this specific features, PALS might be used in further research protocols and clinical studies for cancer diagnostic purposes. This article reports the progress in the study design, main objectives of the study, protocols of measurement sand data analysis and further perspective of this study. The main goal of this work was to show the effectiveness of this method and progress in its development. For this purpose, colorectal cancer was examined.
The possibility of an appropriate neutron beam achievement for medical purposes based on GEANT4 calculations
V. Ivanyan
abstract
Proton-induced reactions on the 9Be target are considered as a neutron source, and dependence of neutron yield on target thicknesses is investigated. The optimal thickness of the 9Be target with the design and optimization characteristics of a beam shaping assembly (BSA) for neutron flux from the thick target is studied with the GEANT4 program. To create the realistic model of the experiment, there are inserted two physics lists for nuclear and electromagnetic reactions. To get a high flux of neutrons had taken into account usage of special materials as moderators on the base of (n, 2n) nuclear reactions, as well as, moderators which will decrease the energy of neutrons to achieve the appropriate thermal/epithermal neutron flux. The creation of the system, which must be made from reflectors and moderators, is a necessity to explore the possibility of an appropriate neutron flux achievement for medical purposes, especially for boron neutron capture therapy (BNCT). GEANT4 simulations of this scientific paper describe the study of IBA's C18/18 cyclotron-based neutron sources and its possible usage for therapies.
Application of silicon-polymer composite varistors to protect sensitive medical imaging circuits and performing better voltage bias for SiPMs
F. Tayefi Ardebili, M. Ghafouri
abstract
Nowadays, Silicon photomultipliers (SiPM) become a reasonable choice
for Time-of-Flight Positron Emission Tomography (TOF-PET). To achieve
the best performance of SiPMs, it is necessary to adjust a suitable voltage
bias. In this article, we are using varistors which protect SiPM from voltage
fluctuations. The silicon-polymer composite varistors prepared using hot
press method have been investigated. Research on (current-voltage) characteristics of samples shows that by increasing silicon content in the mixture, the breakdown voltage decreases from 110 V to 70 V. The results also
show that increasing silicon content decreases the potential barrier height
from 0.29 eV to 0.26 eV, however, leakage current increases. Increasing
silicon content increases nonlinear coefficient from 4.1 to 4.8. Using these
techniques gives us ability to produce suitable surge protector for medical
imaging modalities.
Gate simulation study of the 24-module J-PET scanner: data analysis and image reconstruction
M. Dadgar, P. Kowalski, for the J-PET Collaboration
abstract
The Jagiellonian Positron Emission Tomograph (J-PET) is a novel PET
device that, in contrast to commercial PET scanners, is based on plastic
scintillator strips. Modular J-PET is the latest prototype that consists
of 24 modules arranged in a cylinder. In this study, 6 point-like sources
defined in the NEMA spatial resolution standard were simulated twice with
total activities of 60 kBq and 60 MBq, respectively. Results of simulations
were processed with the GOJA software and reconstructed with the QETIR
package
Vacuum energy with mass generation and Higgs bosons
S.D. Bass, J. Krzysiak
abstract
We discuss the Higgs mass and cosmological constant hierarchy puzzles with emphasis on the interplay of Poincare invariance, mass generation and renormalization group invariance. A plausible explanation involves an emergent Standard Model with the cosmological constant scale suppressed by power of the large scale of emergence. In this scenario the cosmological constant scale and neutrino masses should be of similar size.
Non-mesonic decay of the eta-mesic 3He via pd->(3He-eta)bound 3He2gamma(6gamma) reaction
M. Skurzok, S. Hirenzaki, S. Kinutani, H. Konishi, P. Moskal, H. Nagahiro, O. Rundel
abstract
In this article a theoretical model for the eta-mesic 3He non-mesonic decay channels is presented. We present the resultant relative momentum distribution of bound 3He-eta as well as in-medium branching ratios of eta->2gamma and eta->3pi0, which are crucial for the Monte Carlo simulations of measured processes and thus for the experimental data interpretation. As an example we also apply the model for the estimation of the detection efficiency of the WASA-at-COSY detector.
Search for eta-mesic Helium with WASA-at-COSY
M. Skurzok
abstract
We report on the search for 4 He-eta and 3 He-eta mesic nuclei with WASA-at-COSY detection system. The description of the experimental method as well as recent status of the data analysis are presented.
Revisiting the Charged Kaon Mass
D. Bosnar, M. Bazzi, M. Cargnelli, A. Clozza, C. Curceanu, R. Del Grande, C. Guaraldo, M. Iliescu, M. Makek, J. Marton, M. Miliucci, L. De Paolis, K. Piscicchia, A. Scordo, D.L. Sirghi, F. Sirghi, M. Skurzok, M. Tüchler, J. Zmeskal, P. Žugec
abstract
The precision of the charged kaon mass is an order of magnitude worse than the precision of the charged pion mass mainly due to two inconsistent measurements. We plan to improve this precision by determining the charged kaon mass with the requested accuracy in the measurements of X-ray transitions in kaonic atoms of selected solid targets with the HPGe detector at DAFNE in Laboratori Nazionali di Frascati, Italy. The measurements will be performed in parallel with SIDDHARTA-2 measurements of X-ray transitions in gaseous targets. The status of the preparation of the measurements will be presented.
Recent Experimental Results on the Low-energy K- Interaction with Nucleons by AMADEUS
R. Del Grande, M. Bazzi, A.M. Bragadireanu, D. Bosnar, M. Cargnelli, C. Curceanu, L. De Paolis, L. Fabbietti, C. Fiorini, F. Ghio, C. Guaraldo, R.S. Hayano, M. Iliescu, M. Iwasaki, P. Levi Sandri, J. Marton, M. Miliucci, P. Moskal, S. Okada, K. Piscicchia, A. Ramos, A. Scordo, M. Silarski, D.L. Sirghi, F. Sirghi, M. Skurzok, A. Spallone, O. Vazquez Doce, E. Widmann, S. Wycech, J. Zmeskal
abstract
Recent results obtained by the AMADEUS Collaboration on the experimental investigation of the K- low-energy interaction with light nuclei are summarised. The step 0 of AMADEUS consists in the analysis of the data collected at the DAFNE collider with the KLOE detector during the 2004/2005 data taking campaign. The low momentum K- particles (pK circ 127 MeV/c) are absorbed in the light nuclei contained in the detector setup (H, 4He, 9Be and 12C) and hyperon-pion/hyperon-nucleons, emitted in the final state, are reconstructed. From the study of Lambda pi- and Lambda p correlated production, important information on the KN strong interaction in the non-perturbative QCD regime are extracted.
Kaonic Deuterium Measurement with SIDDHARTA-2 on DAFNE
C. Curceanu, A. Amirkhani, A. Baniahmad, M. Bazzi, D. Bosnar, M. Bragadireanu, M. Carminati, M. Cargnelli, A. Clozza, L. De Paolis, R. Del Grande, L. Fabbietti, C. Fiorini, F. Ghio, C. Guaraldo, M. Iliescu, M. Iwasaki, P. Levi Sandri, J. Marton, M. Miliucci, P. Moskal, S. Niedźwiecki, S. Okada, D. Pietreanu, K. Piscicchia, A. Scordo, H. Shi, M. Silarski, D.L. Sirghi, F. Sirghi, M. Skurzok, A. Spallone, H. Tatsuno, M. Tüchler, O. Vazquez Doce, E. Widmann, J. Zmeskal
abstract
The interaction of antikaons with nucleons and nuclei in the low-energy regime represents an active research field in hadron physics with still many important open questions. The investigation of light kaonic atoms is, in this context, a unique tool to obtain precise information on this interaction. The most precise kaonic hydrogen measurement to date, together with an exploratory measurement of kaonic deuterium, were carried out by the SIDDHARTA Collaboration at the DAFNE electron-positron collider of LNF-INFN, by combining the excellent quality kaon beam delivered by the collider with new experimental techniques, as fast and precise Silicon-Drift X-ray detectors. The measurement of kaonic deuterium will be realized in the near future by SIDDHARTA-2, a major upgrade of SIDDHARTA.
Search for the 3He-eta Bound State via pd -> pdpi0 Reaction
A. Khreptak, M. Skurzok, O. Rundel
abstract
We present status and perspectives of the search for the eta-mesic helium nuclei via pd -> pdpi0 reaction with the WASA-at-COSY. In this report, the experimental method is shortly described and preliminary excitation function is presented.
A Method for Time Calibration of PET Systems Using Fixed beta+ Radioactive Source
K. Dulski, M. Silarski, P. Moskal
abstract
The Positron Emission Tomography (PET) is one of the most popular imaging techniques of the human body. During the PET scans, a positron from the beta+ emitter given to the patient, directly or after forming a positronium, annihilates with an electron from the patient, with emission of photons. Registration of produced photons allows one to reconstruct the distribution of radioisotopes in the patient's body, further interpreted as the metabolic image. The imaging of metabolism can be improved by measurement of the time difference between registration of the two photons in coincidence (Time-of-Flight (TOF))[1]. In the case of the TOF-PET scanners, the time resolution of the detection system and its calibration is crucial. The Jagiellonian Positron Emission Tomograph (J-PET) detector is an example of the TOF-PET system, constructed at the Jagiellonian University in Kraków, which is based on plastic scintillators and very fast electronics
Melanoma spheroids as a model for cancer imaging study
E. Ł. Stępień, H. Karimi, B. Leszczyński, M. Szczepanek
abstract
In contrast to standard 2D cell cultures, spheroids are three-dimensional (3D) models which can mimic natural conditions of cancer growth and metabolism. Their complex structure can be investigated and analyzed using fluorescence microscopy and micro-tomographic imaging (micro-CT) as a new technique. In this study, we show application of two different melanoma cell lines (WM115 and WM266) with different biological characteristics to form spheroids by a hanging drop method.
Application of multivariate analysis in search of the Ks->3pi0 decay in the KLOE experiment
S. Parzych
abstract
According to the Standard Model, one of the purely CP-violating processes is the never observed KS->3pi0 decay. The best upper limit on the branching ratio of this process BR(KS->3p0)<2.6×10^-8 was obtained in the KLOE experiment using cut-based analysis. In this paper, we show preliminary results of an alternative approach to those studies using multivariate analysis methods.
Spectroscopy of eta'-mesic Nuclei with WASA at GSI/FAIR
Y.K. Tanaka, S. Bagchi, J. Benlliure, T. Dickel, V. Drozd, H. Ekawa, H. Fujioka, H. Geissel, F. Goldenbaum, C. Guo, E. Haettner, M.N. Harakeh, R.S. Hayano, S. Hirenzaki, C. Hornung, Y. Igarashi, N. Ikeno, K. Itahashi, M. Iwasaki, D. Jido, N. Kalantar-Nayestanaki, R. Kanungo, B. Kindler, R. Knöbel, D. Kostyleva, N. Kurz, N. Kuzminchuk, B. Lommel, Y. Ma, S.Y. Matsumoto, V. Metag, S. Minami, P. Moskal, I. Mukha, T. Nagae, H. Nagahiro, M. Nakagawa, H.J. Ong, H. Outa, S. Pietri, W.R. Plass, A. Prochazka, S. Purushothaman, C. Rappold, J. Ritman, J.L. Rodríguez-Sánchez, R. Ruber, O. Rundel, T.R. Saito, C. Scheidenberger, R. Sekiya, V. Serdyuk, H. Simon, B. Sitar, M. Skurzok, P. Strmen, B. Sun, I. Szarka, M. Takechi, I. Tanihata, S. Terashima, H. Weick, A. Yamamoto, J. Zhao
abstract
We plan to conduct an experimental search for eta'-mesic nuclei in order to investigate in-medium properties of the eta meson. A 2.5 GeV proton beam is employed to produce eta'-mesic 11C nuclei with the 12C(p,d) eta' at 11C reaction. Simultaneous measurements of the forward ejected deuterons and decay protons from eta'-mesic nuclei will allow us to achieve high experimental sensitivity. The experiment will be performed at GSI by making full use of the fragment separator FRS and the WASA detector system. The plan of this proposed experiment is described.
Construction of the Vacuum Chambers for J-PET Experiments with Positron Annihilation
Marek Gorgol, Bożena Jasińska, Marek Kosior, Eugeniusz Stępień, Paweł Moskal
abstract
Vacuum chambers are necessary for the physics experiments planned to be carried out with the use of the J-PET detector. Two chambers manufactured and used for particular runs of experiments had generally cylindrical shapes, while the radioactive source was placed in the center of each chamber. The highly porous material, used as a target in which positrons positronium atoms annihilate, was placed in the immediate vicinity of the source. Such orientation ensures the axially symmetrical response of J-PET scintillators and allows to carry out correct calibration. The variation of material used for manufacturing of the chambers (aluminum/plastic), allows to observe the detector response with various rates of absorption and scattering of annihilation quanta. Such determination is necessary for proper analysis of multi-quanta annihilation, which will be needed for planned experiments.
Search for the charge symmetry forbidden decays of electron-positron bound state using the J-PET detector
J. Chhokar on behalf J-PET collaboration
abstract
The Jagiellonian Positron Emission Tomograph (J-PET) is a multi-purpose device built out of plastic scintillators. With large acceptance and high angular resolution, it is suitable for the studies of various phenomena such as discrete symmetries in decay of positronium atom or entangled states of photons as well as medical imaging. J-PET enables the measurement of momenta together with photon polarization related observables. Large acceptance and high granularity of the J-PET detector enables measurement of ortho-positronium decays into three photons in the whole phase space. In this paper, we present the search of the C-forbidden decays of positronium with the J-PET detector.
Technical Design Report for the PANDA Endcap Disc DIRC
F. Davi, ..., P. Moskal, et al. (PANDA Collaboration)
abstract
PANDA (anti-Proton ANnihiliation at DArmstadt) is planned to be one of the four main experiments at the future international accelerator complex FAIR (Facility for Antiproton and Ion Research) in Darmstadt, Germany. It is going to address fundamental questions of hadron physics and quantum chromodynamics using cooled antiproton beams with a high intensity and and momenta between 1.5 and 15 GeV/c. PANDA is designed to reach a maximum luminosity of 2x10^32 cm^2 s. Most of the physics programs require an excellent particle identification (PID). The PID of hadronic states at the forward endcap of the target spectrometer will be done by a fast and compact Cherenkov detector that uses the detection of internally reflected Cherenkov light (DIRC) principle. It is designed to cover the polar angle range from 5° to 22° and to provide a separation power for the separation of charged pions and kaons up to 3 standard deviations (s.d.) for particle momenta up to 4 GeV/c in order to cover the important particle phase space. This document describes the technical design and the expected performance of the novel PANDA Disc DIRC detector that has not been used in any other high energy physics experiment (HEP) before. The performance has been studied with Monte-Carlo simulations and various beam tests at DESY and CERN. The final design meets all PANDA requirements and guarantees suffcient safety margins.
Investigations on physical and biological range uncertainties in Krakow proton beam therapy centre
A. Rucinski, J. Baran, G. Battistoni, A. Chrostowska, M. Durante, J. Gajewski, M. Garbacz, K. Kisielewicz, N. Krah, V. Patera, M. Pawlik-Niedźwiecka, I. Rinaldi, B. Rozwadowska-Bogusz, E. Scifoni, A. Skrzypek, F. Tommasino, A. Schiavi, P. Moskal
abstract
Physical and biological range uncertainties limit the clinical potential of Proton Beam Therapy (PBT). In this proceedings, we report on two research projects, which we are conducting in parallel and which both tackle the problem of range uncertainties. One aims at developing software tools and the other at developing detector instrumentation. Regarding the first, we report on our development and pre-clinical application of a GPU-accelerated Monte Carlo (MC) simulation toolkit Fred. Concerning the letter, we report on our investigations of plastic scintillator based PET detectors for particle therapy delivery monitoring. We study the feasibility of Jagiellonian-PET detector technology for proton beam therapy range monitoring by means of MC simulations of the beta+ activity induced in a phantom by proton beams and present preliminary results of PET image reconstruction. Using a GPU-accelerated Monte Carlo simulation toolkit Fred and plastic scintillator based PET detectors we aim to improve patient treatment quality with protons.
Development of J-PEM for breast cancer detection and diagnosis using positronium imaging
Shivani, E. Łuczyńska, S. Heinze, P. Moskal
abstract
The purpose of the presented investigations is to design, construct and establish the characteristic performance of the Jagiellonian Positron Emission Mammography(J-PEM), being designed for the detection and diagnosis of breast cancer. Its construction is based on a novel idea of PET tomography based on plastic scintillators and wavelength shifter (WLS) and a new concept of positronium imaging. We have prepared a simulation program based on Monte Carlo methods for optimizing the geometry and material of the J-PEM prototype. Here we present the first results from the simulations and a brief review of the state of art of breast imaging modalities and their characteristics motivating our investigation.
Towards time reversal symmetry test with o-PS decays using the J-PET detector
J. Raj, K. Dulski, E. Czerwiński
abstract
One of the features of the triplet state of positronium (ortho-positronium) atoms is its relatively longer lifetime when compared to the singlet states of positronium (para-positronium) atoms. The most probable decay of orthopositronium is into three annihilation photons. In order to test the discrete symmetry using the time-reversal symmetry odd-operator, it is important to identify ortho-positronium decay. Identification of the decay of orthopositronium atoms by measuring the positronium annihilation lifetime with the Jagiellonian-Positron Emission Tomograph (J-PET) is presented in this article.
Odd-even staggering in the yields of intermediate mass fragments from p+Ag collisions at Ep = 480 MeV
U. Singh, B. Kamys , S. Sharma, K. Pysz
abstract
The experimental total production cross-sections of intermediate-mass fragments (isotopes of Li, Be, B, C, N, O, F, Ne, Na, and Mg) were extracted by integration of d2s/dOmegadE data measured at several angles for p+Ag collisions at proton beam energy of 480 MeV. The total cross sections show typical odd?even staggering (OES) when presented as a function of the atomic number Z of ejectiles. The effect is the strongest for products with N = Z and N = Z + 2. Similar behaviour is observed for theoretical cross sections evaluated in the two-step model in which the first stage of the reaction is described by intranuclear cascade INCL++ and the second stage by GEMINI++ model or by two other models, namely ABLA07 and SMM. The OES seems to be even more pronounced for theoretical than for the experimental cross sections.
Hazardous Substance Detection in Water Environments using Neutron Beams: the SABAT Project
M. Silarski
abstract
The ever-increasing risk of terrorist attacks is a stimulus for seeking new, more effective danger detection methods. The article describes new methods of detecting hazardous materials based on the interaction between neutrons and matter. The status of the design of the device for detecting hazardous materials in water environments based on these methods, currently in development at the Jagiellonian University (Kraków, Poland), will be presented as well.
N-N-N* model calculations for experimental eta-mesic 3He searches
N. G. Kelkar, H. Kamada, M. Skurzok
abstract
The possibility for the existence of the exotic NNN* states is explored with the objective of calculating the N* momentum distribution inside such nuclei. Even though the latter is an essential ingredient for the analysis of the experimental data on the pd->pdpi0, pd->ppppi- and pd->pnnpi+ reactions aimed at finding an eta-mesic 3He, the data analysis is usually performed by approximating the N* momentum distribution by that of a nucleon. Here, we present calculations performed by solving the three-body Faddeev equations to obtain the momentum distribution of the N* inside possible (N* )+np, (N* )0np and (N* )+-d states. The N*
momentum distributions are found to be much narrower than those of the nucleons and influence the data selection criteria.
Feasibility study of the positronium imaging with the J-PET tomograph
P. Moskal, D. Kisielewska, C. Curceanu, E. Czerwiński, K. Dulski, A. Gajos, M. Gorgol, B. Hiesmayr, B. Jasińska, K. Kacprzak, Ł. Kapłon, G. Korcyl, P. Kowalski, W. Krzemień, T. Kozik, E. Kubicz, M. Mohammed, Sz. Niedźwiecki, M. Pałka, M. Pawlik-Niedźwiecka, L. Raczyński, J. Raj, S. Sharma, Shivani, R.Y. Shopa, M. Silarski, M. Skurzok, E. Stępień, W. Wiślicki, B. Zgardzińska
abstract
A detection system of the conventional PET tomograph is set-up to record data from e+ e- annihilation into two photons with energy of 511 keV, and it gives information on the density distribution of a radiopharmaceutical in the body of the object. In this paper we explore the possibility of performing the three gamma photons imaging based on ortho- positronium annihilation, as well as the possibility of positronium average lifetime imaging with the J-PET tomograph constructed from plastic scintillators. For this purposes simulations of the ortho-positronium formation and its annihilation into three photons were performed taking into account distributions of photons' momenta as predicted by the theory of quantum electrodynamics and the response of the J-PET tomograph. In order to test the proposed ortho-positronium lifetime image reconstruction method, we concentrate on the decay of the ortho-positronium into three photons and applications of radiopharmaceuticals labeled with isotopes emitting a prompt gamma quantum. The proposed method of imaging is based on the determination of hit-times and hit-positions of registered photons which enables the reconstruction of the time and position of the annihilation point as well as the lifetime of the ortho-positronium on an event-by-event basis. We have simulated the production of the positronium in a cylindrical phantom composed of a set of different materials in which the ortho-positronium lifetime varied from 2 ns to ~2.9 ns, as expected for ortho-positronium created in the human body. The presented reconstruction method for total-body J-PET like detector allows to achieve a mean lifetime resolution of about 40 ps. Recent Positron Annihilation Lifetime Spectroscopy measurements of cancerous and healthy uterine tissues show that this sensitivity may allow to study the morphological changes in cell structures.
Monte Carlo N-Particle simulations of an underwater chemical threats detection system using neutron activation analysis
P. Sibczyński, M. Silarski, O. Bezshyyko, V. Ivanyan, E. Kubicz, Sz. Niedźwiecki, P. Moskal, J. Raj, S. Sharma and O. Trofimiuk
abstract
In this paper, we present Monte Carlo N-Particle (MCNP) simulations of the system for underwater threat detection using neutron activation analysis developed in the SABAT project. The simulated system is based on a D-T neutron generator emitting 14 MeV neutrons without associated alpha particle detection and equipped with a LaBr3:Ce scintillation detector offering superior energy resolution and allowing for precise identification of activation gamma quanta. The performed simulations show that using the neutron activation analysis method with the designed geometry we are able to identify gamma-rays from hydrogen, carbon, sulphur and chlorine originating from mustard gas in a seawater environment. Our results show that the most efficient way of mustard gas detection is to compare the integral peak ratio for Cl and H.
Simulation studies of annihilation-photon's polarisation via Compton scattering with the J-PET tomograph
N. Krawczyk, B.C. Hiesmayr, J. Chhokar, C. Curceanu, E. Czerwiński, K. Dulski, A. Gajos, M. Gorgol, N. Gupta-Sharma, B. Jasińska, D. Kisielewska, G. Korcyl, P. Kowalski, W. Krzemień, T. Kozik, E. Kubicz, M. Mohammed, Sz. Niedźwiecki, M. Pałka, M. Pawlik-Niedźwiecka, L. Raczyński, J. Raj, K. Rakoczy, Z. Rudy, S. Sharma, Shivani, R.Y. Shopa, M. Silarski, M. Skurzok, W. Wiślicki, B. Zgardzińska, M. Zieliński, P. Moskal
abstract
J-PET is the first positron-emission tomograph (PET) constructed from plastic scintillators. It was optimized for the detection of photons from electron-positron annihilation. Such photons, having an energy of 511 keV, interact with electrons in plastic scintillators predominantly via the Compton effect. Compton scattering is at most probable at an angle orthogonal to the electric field vector of the interacting photon. Thus registration of multiple photon scatterings with J-PET enables to determine the polarization of the annihilation photons. In this contribution we present estimates on the physical limitation in the accuracy of the polarization determination of 511 keV photons with the J-PET detector.
Investigating the Dirac Operator Evaluation with FPGAs
G. Korcyl, P. Korcyl
abstract
In recent years, computational capacity of single Field Programmable Gate Array (FPGA) devices as well as their versatility have increased signifcantly. Adding to that fact, the High Level Synthesis frameworks allowing to program such processors in a high-level language like C++, makes modern FPGA devices a serious candidate as building blocks of a general-purpose High Performance Computing solution. In this contribution we describe benchmarks which we performed using a kernel from the Lattice QCD code, a highly compute-demanding HPC academic code for elementary particle simulations on the newest device from Xilinx, the U250 accelerator card. We describe the architecture of our solution and benchmark its performance on a single FPGA device running in two modes: using either external or embedded memory. We discuss both approaches in detail and provide assessment for the necessary memory throughput and the minimal amount of resources needed to deliver optimal performance depending on the available hardware. Our considerations can be used as guidelines for estimating the performance of some larger, manynode systems.
Positronium in medicine and biology
P. Moskal, B. Jasińska, E. Ł. Stępień, S. D. Bass
abstract
In positron emission tomography, as much as 40% of positron annihilation occurs through the production of positronium atoms inside the patient's body. The decay of these positronium atoms is sensitive to metabolism and could provide information about disease progression. New research is needed to take full advantage of what positronium decays reveal.
The modern era of light kaonic atom experiments
C. Curceanu, C. Guaraldo, M. Iliescu, M. Cargnelli, R. Hayano, J. Marton, J. Zmeskal, T. Ishiwatari, M. Iwasaki, S. Okada, D. L. Sirghi, and H. Tatsuno
abstract
This review covers the modern era of experimental kaonic atom studies, encompassing 20 years of activity, defined by breakthroughs in technological developments which allowed performing a series of long-awaited precision measurements. Kaonic atoms are atomic systems where an electron is replaced by a negatively charged kaon, containing the strange quark, which interacts in the lowest orbits with the nucleus also by the strong interaction. As a result, their study offers the unique opportunity to perform experiments equivalent to scattering at vanishing relative energy. This allows one to study the strong interaction between the antikaon and the nucleon or the nucleus ?at threshold,? namely, at zero relative energy, without the need of ad hoc extrapolation to zero energy, as in scattering experiments. The fast progress achieved in performing precision light kaonic atom experiments, which also solved long-pending inconsistencies with theoretical calculations generated by old measurements, relies on the development of novel cryogenic targets, x-ray detectors, and the availability of pure and intense charged kaon beams, which propelled an unprecedented progress in the field. Future experiments, based on new undergoing technological developments, will further boost the kaonic atom studies, thus fostering a deeper understanding of the low-energy strong interaction extended to the second family of quarks.
Witnessing Entanglement In Compton Scattering Processes Via Mutually Unbiased Bases
B.C. Hiesmayr, P. Moskal
abstract
We present a quantum information theoretic version of the Klein-Nishina formula. This formulation
singles out the quantity, the a priori visibility, that quantifies the ability to deduce the polarisation
property of single photons. The Kraus-type structure allows a straightforward generalisation to the
multiphoton cases, relevant in the decay of positronium which is utilized e.g. for metabolic PETimaging
(Positron- Emission- Tomograph). Predicted by theory but never experimentally proven, the
two- or three-photon states should be entangled. We provide an experimentally feasible method to
witness entanglement for these processes via MUBs (Mutually Unbiased Bases), exploiting Bohr?s
complementarity. Last but not least we present explicit cases exemplifying the interrelation of
geometry and entanglement including relations to its potentiality for teleportation schemes or Bell
inequality violations or in future for detecting cancer in human beings.
X-ray Detectors for Kaonic Atoms Research at DAFNE
C. Curceanu, A. Amirkhani, A. Baniahmad , M. Bazzi, G. Bellotti, C. Berucci, D. Bosnar, M. Bragadireanu, M. Cargnelli, A. Clozza, R. Del Grande, C. Fiorini, F. Ghio, C. Guaraldo, M. Iliescu, M. Iwasaki, P. Levi Sandri, J. Marton, M. Miliucci , P. Moskal, S. Niedźwiecki, S. Okada, D. Pietreanu, K. Piscicchia, A. Scordo, H. Shi, M. Silarski, D. Sirghi, F. Sirghi, M. Skurzok, A. Spallone, H. Tatsuno, O. Vazquez Doce, E. Widmann and J. Zmeskal
abstract
This article presents the kaonic atom studies performed at the INFN National Laboratory of Frascati (Laboratori Nazionali di Frascati dell'INFN, LNF-INFN) since the opening of this field of research at the DAFNE collider in early 2000. Significant achievements have been obtained by the DAFNE Exotic Atom Research (DEAR) and Silicon Drift Detector for Hadronic Atom Research by Timing Applications (SIDDHARTA) experiments on kaonic hydrogen, which have required the development of novel X-ray detectors. The 2019 installation of the new SIDDHARTA-2 experiment to measure kaonic deuterium for the first time has been made possible by further technological advances in X-ray detection
Precision resonance energy scans with the PANDA experiment at FAIR
G. Barucca, ..., P. Moskal, et al. (PANDA Collaboration)
abstract
This paper summarises a comprehensive Monte Carlo simulation study for precision resonance energy scan measurements. Apart from the proof of principle for natural width and line shape measurements of very narrow resonances with PANDA, the achievable sensitivities are quantified for the concrete example of the charmonium-like X(3872) state discussed to be exotic, and for a larger parameter space of various assumed signal cross-sections, input widths and luminosity combinations. PANDA is the only experiment that will be able to perform precision resonance energy scans of such narrow states with quantum numbers of spin and parities that differ from J^PC = 1--
Search for polarized antiproton production
D. Grzonka, D. Alfs, A. Asaturyan, M. Carmignotto, M. Diermaier, W. Eyrich, B. Głowacz, F. Hauenstein, T. Horn, K. Kilian, D. Lersch, S. Malbrunot-Ettenauer, A. Mkrtchyan, H. Mkrtchyan, P. Moskal, P. Nadel-Turonski, W. Oelert, J. Ritman, T. Sefzick, V. Tadevosyan, E. Widmann, M. Wolke, S. Zhamkochyan, M. Zieliński, A. Zink, J. Zmeskal
abstract
The production of antiprotons is studied in view of possible polarization effects as basis for a polarized antiproton beam. If antiprotons are produced with some polarization, a quite simple procedure for the generation of a polarized antiproton beam could be worked out. The experiments are performed at the CERN PS test beam T11 where secondary particles with momenta around 3.5 GeV/c are selected. The polarization analysis is performed by measuring the asymmetry of the elastic pp-scattering in the Coulomb-nuclear interference region. The detection system includes Cherenkov and tracking detectors for the particle identification and the 3d track reconstruction. Details on the detection system and the status of the analysis are given.
K- multi-nucleon absorption cross sections and branching ratios in Lambda p and Sigma0 p final states
R. Del Grande, K. Piscicchia, O. Vazquez Doce, M. Cargnelli, C. Curceanu, L. Fabbietti, J. Marton, P. Moskal, A. Ramos, A. Scordo, D. L. Sirghi, M. Skurzok, S. Wycech, J. Zmeskal, E. Czerwiński, V. De Leo, P. Fermani, G. Mandaglio, M. Martini, N. Raha, A. Selce, M. Silarski
abstract
The determination of low-energy cross sections and branching ratios of the K- multi-nucleon absorption processes in Lambda p and Sigma0 p final states performed by the AMADEUS collaboration is presented. Low momentum K- (pK- ~127 MeV/c) produced at the DAFNE collider are impinged on a Carbon target within the KLOE detector and the two and three nucleon absorption processes are disentangled by comparing the experimental data to phenomenological calculations. The Lambda p spectra entirely interpreted in terms of K- multi-nucleon absorption processes; the possible contribution of a K-pp bound state is demonstrated to overlap with the two nucleon capture process, its absolute yield thus resulting indistinguishable.
Etaprime and Eta Mesons with Connection to Anomalous Glue
S. D. Bass, P. Moskal
abstract
We review the present understanding of etaprime and eta meson physics and these mesons as a probe of gluon dynamics in low-energy QCD. Recent highlights include the production mechanism of eta and etaprime mesons in proton-nucleon collisions from threshold to high-energy, the etaprime effective mass shift in the nuclear medium, searches for possible eta and etaprime bound states in nuclei as well as precision measurements of eta decays as a probe of light-quark masses. We discuss recent experimental data, theoretical interpretation of the different measurements and the open questions and challenges for future investigation.
Technical Design Report for the PANDA Barrel DIRC Detector
B. Singh, ..., B. Kamys, G. Korcyl, W. Krzemien, P. Moskal, et al. (PANDA Collaboration)
abstract
This documents describes the technical design and the expected performance of the Barrel DIRC detector for the PANDA experiment. The Barrel DIRC will provide hadronic charged particle identification in the polar angle range of 22 [deg] to 140 [deg] for particle momenta between 0.5 GeV/c and 3.5 GeV/c. The design is based on the successful BaBar DIRC with several key improvements. The performance and system cost were optimized in detailed detector simulations and validated with full system prototypes using particle beams at GSI and CERN. The final design meets or exceeds the PID goal of clean pi/K separation with at least 3 standard deviations over the entire phase space of charged kaons in the Barrel DIRC.
Examination of the Production of an Isotensor Dibaryon in the pp->pppi+pi- Reaction
P. Adlarson, ..., E. Czerwiński, O. Khreptak, W. Krzemień, P. Moskal, O. Rundel, I. Schätti-Ozerianska, M. Skurzok, M.J. Zieliński, et al.
abstract
Exclusive measurements of the quasi-free pp->pppi+pi- reaction have been performed by means of pd collisions at Tp = 1.2 GeV using the WASA detector setup at COSY. Total and differential cross sections have been obtained covering the energy region Tp=1.08-1.36 GeV (sqrt(s) = 2.35 - 2.46 GeV), which includes the regions of N*(1440) and Delta(1232)Delta(1232) resonance excitations. Calculations describing these excitations by t-channel meson exchange are at variance with experimental differential cross sections and underpredict substantially the measured total cross section. An isotensor DeltaN dibaryon resonance with I(JP)=2(1+) produced associatedly with a pion is able to overcome these deficiencies. Such a dibaryon was predicted by Dyson and Xuong and more recently calculated by Gal and Garcilazo.
QED and Fundamental Symmetries in Positronium Decays
Steven D. Bass
abstract
We discuss positronium decays with emphasis on tests of fundamental symmetries and the constraints from measurements of other precision observables involving electrons and photons.
Feasibility studies of the polarization of photons beyond the optical wavelength regime with the J-PET detector
P. Moskal, N. Krawczyk, B. C. Hiesmayr, M. Bała, C. Curceanu, E. Czerwinski, K. Dulski, A. Gajos, M. Gorgol, R. Del Grande, B. Jasinska, K. Kacprzak, L. Kapłon, D. Kisielewska, K. Klimaszewski, G. Korcyl, P. Kowalski, T. Kozik, W. Krzemien, E. Kubicz, M. Mohammed, Sz. Niedźwiecki, M. Pałka, M. Pawlik-Niedźwiecka, L. Raczynski, J. Raj, Z. Rudy, S. Sharma, M. Silarski, Shivani, R. Y. Shopa, M. Skurzok, W. Wislicki, B. Zgardzinska
abstract
J-PET is a detector optimized for registration of photons from the electron-positron annihilation via plastic scintillators where photons interact predominantly via Compton scattering. Registration of both primary and scattered photons enables to determinate the linear polarization of the primary photon on the event by event basis with a certain probability. Here we present quantitative results on the feasibility of such polarization measurements of photons from the decay of positronium with the J-PET and explore the physical limitations for the resolution of the polarization determination of 511keV photons via Compton scattering. For scattering angles of about 82 degree (where the best contrast for polarization measurement is theoretically predicted) we find
that the single event resolution for the determination of the polarization is about 40 degree (predominantly due to properties
of the Compton effect). However, for samples larger than ten thousand events the J-PET is capable of determining relative average polarization of these photons with the precision of about few degrees. The obtained results open new perspectives for studies of various physics phenomena such as quantum entanglement and tests of discrete symmetries in decays of positronium and extend the energy range of polarization measurements by five orders of magnitude beyond the optical wavelength regime.
Evaluation of Single-Chip, Real-Time Tomographic Data Processing on FPGA - SoC Devices
G. Korcyl, P. Białas, C. Curceanu, E. Czerwiński, K. Dulski, B. Flak, A. Gajos, B. Głowacz, M. Gorgol, B. C. Hiesmayr, B. Jasińska, K. Kacprzak, M. Kajetanowicz, D. Kisielewska, P. Kowalski, T. Kozik, N. Krawczyk, W. Krzemień, E. Kubicz, M. Mohammed, Sz. Niedźwiecki, M. Pawlik- Niedźwiecka, M. Pałka, L. Raczyński, P. Rajda, Z. Rudy, P. Salabura, N. G. Sharma, S. Sharma, R. Y. Shopa, M. Skurzok, M. Silarski, P. Strzempek, A. Wieczorek, W. Wiślicki, R. Zaleski, B. Zgardzińska, M. Zieliński, P. Moskal
abstract
A novel approach to tomographic data processing
has been developed and evaluated using the Jagiellonian PET (J-
PET) scanner as an example. We propose a system in which there
is no need for powerful, local to the scanner processing facility,
capable to reconstruct images on the fly. Instead we introduce a
Field Programmable Gate Array (FPGA) System-on-Chip (SoC)
platform connected directly to data streams coming from the
scanner, which can perform event building, filtering, coincidence
search and Region-Of-Response (ROR) reconstruction by the
programmable logic and visualization by the integrated
processors. The platform significantly reduces data volume
converting raw data to a list-mode representation, while
generating visualization on the fly.
Lyman-alpha source for laser cooling antihydrogen
G. Gabrielse, B. Glowacz, D. Grzonka, C. D. Hamley, E. A. Hessels, N. Jones, G. Khatri, S. A. Lee, C. Meisenhelder, T. Morrison, E. Nottet, C. Rasor, S. Ronald, T. Skinner, C. H. Storry, E. Tardiff, D. Yost, D. Martinez Zambrano, M. Zieliński
abstract
We present a Lyman-alpha laser developed for cooling trapped antihydrogen. The system is based on a pulsed Ti:sapphire laser operating at 729 nm that is frequency doubled using an LBO crystal and then frequency tripled in a Kr/Ar gas cell. After frequency conversion, this system produces up to 5.7 mW of average power at the Lyman-alpha wavelength. This laser is part of the ATRAP experiment at the antiproton decelerator in CERN.
A feasibility study of the time reversal violation test based on polarization of annihilation photons from the decay of ortho-Positronium with the J-PET detector
J. Raj, A. Gajos, C. Curceanu, E. Czerwiński, K. Dulski, M. Gorgol, N. Gupta-Sharma, B. C. Hiesmayr, B. Jasińska, K. Kacprzak, Ł. Kapłon, D. Kisielewska, K. Klimaszewski, G. Korcyl, P. Kowalski, T. Kozik, N. Krawczyk, W. Krzemień, E. Kubicz, M. Mohammed, Sz. Niedźwiecki, M. Pałka, M. Pawlik-Niedźwiecka, L. Raczyński, K. Rakoczy, Z. Rudy, S. Sharma, Shivani, R.Y. Shopa, M. Silarski, M. Skurzok, W. Wiślicki, B. Zgardzińska, P. Moskal
abstract
The Jagiellonian Positron Emission Tomograph (J-PET) is a novel device being developed at Jagiellonian University in Krakow, Poland based on organic scintillators. J-PET is an axially symmetric and high acceptance scanner that can be used as a multi-purpose detector system. It is well suited to pursue tests of discrete symmetries in decays of positronium in addition to medical
imaging. J-PET enables the measurement of both momenta and the polarization vectors of annihilation photons. The latter is a unique feature of the J-PET detector which allows the study of time reversal symmetry violation operator which can be constructed solely from the annihilation photons momenta before and after the scattering in the detector.
Commissioning of the J-PET detector in view of the positron annihilation lifetime spectroscopy
K. Dulski, C. Curceanu, E. Czerwiński, A. Gajos, M. Gorgol, N. Gupta-Sharma, B. C. Hiesmayr, B. Jasińska, K. Kacprzak, Ł. Kapłon, D. Kisielewska, K. Klimaszewski, G. Korcyl, P. Kowalski, N. Krawczyk, W. Krzemień, T. Kozik, E. Kubicz, M. Mohammed, Sz. Niedźwiecki, M. Pałka, M. Pawlik-Niedźwiecka, L. Raczyński, J. Raj, K. Rakoczy, Z. Rudy, S. Sharma, Shivani, R. Y. Shopa, M. Silarski, M. Skurzok, W. Wiślicki, B. Zgardzińska, P. Moskal
abstract
The Jagiellonian Positron Emission Tomograph (J-PET) is the first PET device built from plastic scintillators. It is a multi-purpose detector designed for medical imaging and for studies of properties of positronium atoms in porous matter and in living organisms. In this article we report on the commissioning of the J-PET detector in view of studies of positronium decays. We present results of analysis of the positron lifetime measured in the porous polymer. The obtained results prove that J-PET is capable of performing simultaneous imaging of the density distribution of annihilation points as well as positron annihilation lifetime spectroscopy.
Backward single-pion production in the pd->3Hepi0 reaction with WASA-at-COSY
P. Adlarson, ..., E. Czerwiński, O. Khreptak, W. Krzemień, P. Moskal, O. Rundel, I. Schätti-Ozerianska, M. Skurzok, M.J. Zieliński, et al.
abstract
New data on the production of single neutral pions in the pd->3Hepi0 reaction are presented. For fifteen proton beam momenta between pp=1.60GeV/c and pp=1.74GeV/c, differential cross sections are determined over a large fraction of the backward hemisphere. Since the only previous systematic measurements of single-pion production at these energies were made in collinear kinematics, the present work constitutes a significant extension of the current knowledge on this reaction. Even this far above the production threshold, significant changes are found in the behaviour of the angular distributions over small intervals in beam momentum.
Measurement of the charge asymmetry for the KS->pi e nu decay and test of CPT symmetry with the KLOE detector
The KLOE-2 collaboration: A. Anastasi, E. Czerwiński, A. Gajos, D. Kisielewska-Kamińska, W. Krzemień, P. Moskal, M. Silarski, W. Wiślicki, et al.
abstract
Using 1.63 fb^(-1) of integrated luminosity collected by the KLOE experiment about 7 10^4 KS->pi e nu decays have been reconstructed. The measured value of the charge asymmetry for this decay is AS=(-4.9 pm 5.7_{stat} pm 2.6_{syst}) 10^(-3), which is almost twice more precise than the previous KLOE result. The combination of these two measurements gives AS=(-3.8 pm 5.0_{stat} pm 2.6_{syst}) 10^(-3) and, together with the asymmetry of the KL semileptonic decay, provides significant tests of the CPT symmetry. The obtained results are in agreement with CPT invariance.
Feasibility study of the time reversal symmetry tests in decay of metastable positronium atoms with the J-PET detector
A. Gajos, C. Curceanu, E. Czerwinski, K. Dulski, M. Gorgol, N. Gupta-Sharma, B.C. Hiesmayr, B. Jasinska, K. Kacprzak, L. Kaplon, D. Kisielewska, G. Korcyl, P. Kowalski, T. Kozik, W. Krzemien, E. Kubicz, M. Mohammed, Sz Niedzwiecki, M. Paalka, M. Pawlik-Niedzwiecka, L. Raczynski, J. Raj, Z. Rudy, S. Sharma, Shivani, R. Shopa, M. Silarski, M. Skurzok, W. Wislicki, B. Zgardzinska, M. Zielinski, P. Moskal
abstract
This article reports on the feasibility of testing of the symmetry under reversal in time in a purely leptonic system constituted by positronium atoms using the J-PET detector. The present state of T symmetry tests is discussed with an emphasis on the scarcely explored sector of leptonic systems. Two possible strategies of searching for manifestations of T violation in non-vanishing angular correlations of final state observables in the decays of metastable triplet states of positronium available with J-PET are proposed and discussed. Results of a pilot measurement with J-PET and assessment of its performance in reconstruction of three-photon decays are shown along with an analysis of its impact on the sensitivity of the detector for the determination of T -violation sensitive observables.
Strong interaction between kaons in the reactions e+e- -> K+K- gamma and e+ e- ->K0K0gamma
L. Leśniak, F. Sobczuk, M. Silarski, and F. Morawski
abstract
A theoretical model of the reactions e+e- -> K+K-gamma and e+e- -> K0K0gamma has been derived. The strong interaction between kaons is taken into account using a general form of the KK scattering amplitude. It is shown that some models formulated in the past are particular cases of the present approach. The formulas for the K+K- effective mass dependence of the differential cross section as well as for the angular kaon and photon distributions and for the branching fractions of the phi(1020) -> K-K+gamma and phi(1020) -> K0K0-gamma decays have been obtained. We present numerical results for the functions entering into transition amplitudes, KK? effective mass distributions, total cross sections, and branching fractions. Finally, the model is generalized to treat other reactions with two pseudoscalar mesons accompanying a photon in the final state.
Combined limit on the production of a light gauge boson decaying into mu+ mu- and pi+pi-
The KLOE-2 collaboration: A. Anastasi, E. Czerwiński, A. Gajos, D. Kisielewska-Kamińska, W. Krzemień, P. Moskal, M. Silarski, W. Wiślicki, et al.
abstract
We searched for the decay of a light vector gauge boson, also known as dark photon, in the process by means of the Initial State Radiation (ISR) method. We used 1.93 fb^-1 of data collected by the KLOE experiment at the DAFNE phi-factory. No structures have been observed over the irreducible background. A 90% CL limit on the ratio between the dark coupling constant and the fine structure constant of has been set in the dark photon mass region between 519 MeV and 973 MeV. This new limit has been combined with the published result obtained investigating the hypothesis of the dark photon decaying into hadrons in events. The combined 90% CL limit increases the sensitivity especially in the rho-omega interference region and excludes greater than . For dark photon masses greater than 600 MeV the combined limit is lower than 8 resulting more stringent than present constraints from other experiments.
Search for C violation in the decay eta->pi0 e+e- with WASA-at-COSY
P. Adlarson, ...,P. Moskal,...A. Pyszniak,..., Z. Rudy,..., M. Skurzok, et al. (WASA-at-COSY Collaboration)
abstract
We report on the investigation of the rare decay eta->pi0 e+e which is of interest to study both C violation in the electromagnetic interaction and to search for contributions from physics beyond the Standard Model, since the allowed decay via a two-photon intermediate state is strongly suppressed. The experiment has been performed using the WASA-at-COSY installation, located at the COSY accelerator of the Forschungszentrum Juelich, Germany. In total 3×10^7 events of the reaction p+d->3He eta have been recorded at an excess energy of Q=59.8MeV. Based on this data set the C parity violating decay eta->pi0 g* -> pi0e+e- via a single-photon intermediate state has been searched for, resulting in new upper limits of Gamma(eta->pi0e+e-)/Gamma(eta->pi+pi-pi0)<3.28×10^-5 and Gamma(eta->pi0e+e-)/Gamma(eta-> all)<7.5×10^-6 (CL=90%), respectively.
Updating spin-dependent Regge intercepts
S. D. Bass, M. Skurzok, P. Moskal
abstract
We use new high statistics data from CLAS and COMPASS on the nucleon's spin structure function at low Bjorken x and low virtuality, Q^2 < 0.5 GeV^2, together with earlier measurements from the SLAC E-143, HERMES and GDH experiments to estimate the effective intercept(s) for spin dependent Regge theory. We find alpha_{a_1} = 0.31 pm 0.04 for the intercept describing the high-energy behaviour of spin dependent photoabsorption together with a new estimate for the high-energy part of the Gerasimov-Drell-Hearn sum-rule, -15 pm 2 mu b from photon-proton centre-of-mass energy greater than 2.5 GeV. Our value of alpha_{a_1} suggests QCD physics beyond a simple straight-line a_1 trajectory.
Estimating the NEMA characteristics of the J-PET tomograph using the GATE package
P. Kowalski, W. Wiślicki, R.Y. Shopa, L. Raczyński, K. Klimaszewski, C. Curcenau, E. Czerwiński, K. Dulski, A. Gajos, M. Gorgol, N. Gupta-Sharma, B. Hiesmayr, B. Jasińska, Ł. Kapłon, D. Kisielewska-Kamińska, G. Korcyl, T. Kozik, W. Krzemień, E. Kubicz, M. Mohammed, S. Niedźwiecki, M. Pałka, M. Pawlik-Niedźwiecka, J. Raj, K. Rakoczy, Z. Rudy, S. Sharma, S. Shivani, M. Silarski, M. Skurzok, B. Zgardzińska, M. Zieliński, P. Moskal
abstract
A novel whole-body positron emission tomography (PET) system based on plastic scintillators is
developed by the J-PET Collaboration. It consists of plastic scintillator strips arranged axially in the
form of a cylinder, allowing the cost-effective construction of the total-body PET system. In order to
determine the properties of the scanner prototype and optimize its geometry, advanced computer
simulations were performed using the GATE (Geant4 application for tomographic emission)
software.
The spatial resolution, sensitivity, scatter fraction and noise equivalent count rate were estimated
according to the National Electrical Manufacturers Association norm, as a function of the length
of the tomograph, the number of detection layers, the diameter of the tomographic chamber and
for various types of applied readout. For the single-layer geometry with a diameter of 85 cm, a strip
length of 100 cm, a cross-section of 4 mm × 20 mm and silicon photomultipliers with an additional
layer of wavelength shifter as the readout, the spatial resolution (full width at half maximum) in
the centre of the scanner is equal to 3 mm (radial, tangential) and 6 mm (axial). For the analogous
double-layer geometry with the same readout, diameter and scintillator length, with a strip crosssection
of 7 mm × 20 mm, a noise equivalent count rate peak of 300 kcps was reached at 40 kBq cc?1
activity concentration, the scatter fraction is estimated to be about 35% and the sensitivity at the
centre amounts to 14.9 cps kBq?1. Sensitivity profiles were also determined.
Isotensor Dibaryon in the pp->pppi+pi- Reaction?
P. Adlarson, ..., E. Czerwiński, O. Khreptak, W. Krzemień, P. Moskal, O. Rundel, I. Schätti-Ozerianska, M. Skurzok, M.J. Zieliński, et al.
abstract
Exclusive measurements of the quasi-free pp->pppi+pi- reaction have been carried out at WASA@COSY by means of pd collisions at Tp = 1.2 GeV. Total and differential cross sections have been extracted covering the energy region Tp=1.08-1.36 GeV, which is the region of N*(1440) and Delta(1232)Delta(1232) resonance excitations. Calculations describing these excitations by t-channel meson exchange are at variance with the measured differential cross sections and underpredict substantially the experimental total cross section. An isotensor DeltaN dibaryon resonance with I(JP)=2(1+) produced associatedly with a pion is able to overcome these deficiencies.
First measurement of the K-n->Lambda pi- non-resonant transition amplitude below threshold
K. Piscicchia, S. Wycech, L. Fabbietti, M. Cargnelli, C. Curceanu, R. Del Grande, J. Marton, P. Moskal, A. Scordo, M. Silarski, D. Sirghi, M. Skurzok, I. Tucakovic, O. Vazquez Doce, J. Zmeskal, P. Branchini, E. Czerwinski, V. De Leo, E. De Lucia, A. Di Cicco, P. Fermani, S. Fiore, W. Krzemien, G. Mandaglio, M. Martini, E. Perez del Rio , A. Selce
abstract
We present the analysis of K- absorption processes on 4He leading to Lambda pi- final states, measured with the KLOE e+e- spectrometer at the DAFNE collider and extract, for the first time, the modulus of the non-resonant K-n->Lambda pi- direct production amplitude about 33 MeV below the KbarN threshold. This analysis also allows to disentangle the K- nuclear absorption at-rest from the in-flight capture, for K- momenta of about 120 MeV. The data are interpreted with the help of a phenomenological model, and the modulus of the non-resonant K-n->Lambda pi- amplitude for K- absorption at-rest is found to be |A_K-n->Lambda pi-| = (0.334+-0.018(stat.)+0.034 -0.058 (syst.)) fm.
Total and differential cross sections of eta-production in proton-deuteron fusion for excess energies between Q_eta=13MeV and Q_eta=81MeV
P. Adlarson, ...,E. Czerwiński, A. Khreptak, W. Krzemień, P. Moskal, O. Rundel, M. Skurzok, I. Schätti-Ozerianska, M. Zieliński, et al. (WASA-at-COSY Collaboration)
abstract
New data on both total and differential cross sections of the production of eta mesons in proton-deuteron fusion to 3He-eta in the excess energy region 13.6MeV < Q < 80.9 MeV are presented. These data have been obtained with the WASA-at-COSY detector setup located at the Forschungszentrum Julich, using a proton beam at 15 different beam momenta between p_p=1.60GeV/c and p_p=1.74GeV/c. While significant structure of the total cross section is observed in the energy region 20 MeV < Q < 60MeV, a previously reported sharp variation around Q ~ 50MeV cannot be confirmed. Angular distributions show the typical forward-peaking that was reported elsewhere. For the first time, it is possible to study the development of these angular distributions with rising excess energy over a large interval.
Constraining the optical potential in the search for eta-mesic 4He
M. Skurzok, P. Moskal, N.G. Kelkar, S. Hirenzaki, H. Nagahiro, N. Ikeno
abstract
A consistent description of the dd-> 4He eta and dd-> (4He-eta)bound X cross sections was recently proposed with a broad range of real (V0) and imaginary (W0), eta-4He optical potential parameters leading to a good agreement with the d d -> 4He eta data. Here we compare the predictions of the model below the eta production threshold, with the WASA-at-COSY excitation functions for the dd -> 3He N pi reactions to put stronger constraints on (V0, W0). The allowed parameter space (with |V_0| < sim 60 MeV and |W_0| < sim 7 MeV estimated at 90% CL ) excludes most optical model predictions of eta-4He nuclei except for some loosely bound narrow states.
The predictive power of spallation models for isotopic cross sections
U. Singh, D. Filges, F. Goldenbaum, Boguslaw Kamys, Z. Rudy, and S. Sharma
abstract
The experimental cross sections of isotopically identified products of spallation reactions induced
by 136Xe projectiles at 1 GeV/nucleon on hydrogen target were compared with predictions of a two-step
model. The first stage of the reaction was described by the INCL++ model (version 5.3) of an intranuclear
cascade of nucleon-nucleon and pion-nucleon collisions whereas the second stage was analyzed by means
of four different models; ABLA07, GEM2, GEMINI ++ and SMM. Due to the fact that the experimental
data cover a very broad range of elements; from Li (Z=3) to Ba(Z= 56), the analysis could impose severe
constraints on the applied reaction models. The quality of data reproduction by the theoretical models
is discussed. Some systematic deviations of the theoretical predictions from the experimental results are
observed.
Importance of d-wave contributions in the charge symmetry breaking reaction dd->4Hepi0
P. Adlarson, ...,E. Czerwiński, O. Khreptak, W. Krzemień, P. Moskal, O. Rundel, M. Skurzok, M. Zieliński et al. (WASA-at-COSY Collaboration)
abstract
This letter reports the first measurement of the contribution of higher partial waves in the charge symmetry breaking reaction dd->4Hepi0 using the WASA-at-COSY detector setup at an excess energy of Q=60 MeV. The determined differential cross section can be parametrized as dsigma/domega=a+bcos2theta?, where theta? is the production angle of the pion in the center-of-mass coordinate system, and the results for the parameters are a=(1.55+-0.46(stat)+0.32-0.8(syst))pb/sr and b=(13.1+-2.1(stat)+1.0-2.7(syst))pb/sr. The data are compatible with vanishing p-waves and a sizable d-wave contribution. This finding should strongly constrain the contribution of the Delta isobar to the dd->4Hepi0 reaction and is therefore crucial for a quantitative understanding of quark mass effects in nuclear production reactions.
Combination of KLOE sigma(e^+e^- e -> pi^+pi^-g(g)) measurements and determination of a_{mu)^{pi^+pi^-} in the energy range 0.10 < s < 0.95 GeV^2
The KLOE-2 collaboration: A. Anastasi, E. Czerwiński, A. Gajos, D. Kisielewska-Kamińska, W. Krzemień, P. Moskal, M. Silarski, W. Wiślicki, et al.
abstract
The three precision measurements of the cross section sigma(e^+e^- e -> pi^+pi^-g(g)) using initial state radiation by the KLOE collaboration provide an important input for the prediction of the hadronic contribution to the anomalous magnetic moment of the muon. These measurements are correlated for both statistical and systematic uncertainties and, therefore, the simultaneous use of these measurements requires covariance matrices that fully describe the correlations. We present the construction of these covariance matrices and use them to determine a combined KLOE measurement for sigma(e^+e^- e -> pi^+pi^-g(g)). We find, from this combination, a two-pion contribution to the muon magnetic anomaly in the energy range 0.10 < s < 0.95 GeV^2 of a_{mu)^{pi^+pi^-} = (489.8 pm 1.7 stat pm 4.8 sys ) 10^(-10) .
Search for Deeply Bound Kaonic Nuclear States in AMADEUS experiment
M. Skurzok, M. Cargnelli, C. Curceanu, R. Del Grande, L. Fabbietti, C. Guaraldo, J. Marton, P. Moskal, K. Piscicchia, A. Scordo, M. Silarski, D. L. Sirghi, I. Tucakovic, O. Vazquez Doce, S. Wycech, E. Widmann, J. Zmeskal
abstract
We briefly report on the search for Deeply Bound Kaonic Nuclear States with AMADEUS in the Sigma0 p channel and future perspectives.
Investigation of complete and incomplete fusion in the Li 7 + Sn 124 reaction near Coulomb barrier energies
V.V.Parkar, S. Sharma, R. Palit et al.,
abstract
The complete and incomplete fusion cross sections for the 7Li + 124Sn reaction were measured using online and offline characteristic ? -ray detection techniques. The complete fusion (CF) cross sections at energies above the Coulomb barrier were found to be suppressed by ?26% compared to the coupled channel calculations. This suppression observed in complete fusion cross sections is found to be commensurate with the measured total incomplete fusion (ICF) cross sections. There is a distinct feature observed in the ICF cross sections, i.e., t capture is found to be dominant compared to ? capture at all the measured energies. A simultaneous explanation of complete, incomplete, and total fusion (TF) data was also obtained from the calculations based on the continuum discretized coupled channel method with short-range imaginary potentials. The cross-section ratios of CF/TF and ICF/TF obtained from the data, as well as the calculations, showed the dominance of ICF at below-barrier energies and CF at above-barrier energies.
Spin dependence of eta meson production in proton-proton collisions close to threshold
P. Adlarson, ...,E. Czerwiński, O. Khreptak, W. Krzemień, P. Moskal, O. Rundel, M. Skurzok, M. Zieliński et al. (WASA-at-COSY Collaboration)
abstract
Taking advantage of the high acceptance and axial symmetry of the WASA-at-COSY detector, and
the high degree of the polarized proton beam of COSY, the reaction ~pp->pp eta has been measured
close to threshold to explore the analyzing power Ay. The angular distribution of Ay is determined
with the precision improved by more than one order of magnitude with respect to previous results
allowing a first accurate comparison with theoretical predictions. The determined analyzing power
is consistent with zero for an excess energy of Q=15 MeV signaling s wave production with no
evidence for higher partial waves. At Q=72 MeV the data reveals strong interference of Ps and
Pp partial waves and cancellation of (Pp) and Ss?Sd contributions. These results rule out the
presently available theoretical predictions for the production mechanism of the eta meson.
Non-equilibrium processes in p + Ag collisions at GeV energies
M. Fidelus,.., B. Kamys, S. Kistryn, A. Magiera, Z. Rudy, S. Sharma et al.,
abstract
The double differential spectra d2?/d?dE of p, d, t, He3,4,6, Li6,7,8,9, Be7,9,10, and B10,11,12 were measured at seven scattering angles, 15.6?, 20?, 35?, 50?, 65?, 80?, and 100?, in the laboratory system for proton induced reactions on a silver target. Measurements were done for three proton energies: 1.2, 1.9, and 2.5 GeV. The experimental data were compared to calculations performed by means of two-step theoretical microscopic models. The first step of the reaction was described by the intranuclear cascade model incl4.6 and the second one by four different models (ABLA07, GEM2, gemini++, and SMM) using their standard parameter settings. Systematic deviations of the data from predictions of the models were observed. The deviations were especially large for the forward scattering angles and for the kinetic energy of emitted particles in the range from about 50 to 150 MeV. This suggests that some important non-equilibrium mechanism is lacking in the present day microscopic models of proton-nucleus collisions in the studied beam energy range.
A Method to Produce Linearly Polarized Positrons and Positronium Atoms with the J-PET Detector
M. Mohammed, P. Białas, C. Curceanu, E. Czerwiński, K. Dulski, A. Gajos, B. Głowacz, M. Gorgol, B.C. Hiesmayr, B. Jasińska, D. Kisielewska, G. Korcyl, P. Kowalski, T. Kozik, N. Krawczyk, W. Krzemień, E. Kubicz, M. Pawlik-Niedźwiecka, S. Niedźwiecki, M. Pałka, L. Raczyński, J. Raj, Z. Rudy, N.G. Sharma, S. Sharma, Shivani, M. Skurzok, M. Silarski, A. Wieczorek, W. Wiślicki, B. Zgardzińska, M. Zieliński, P. Moskal
abstract
A method for creating linearly polarized positrons and ortho-positronium (o-Ps) atoms with the J-PET detector is presented. The unique geometry and properties of the J-PET tomography enable one to design a positron source such that the quantization axis for the estimation of the linear polarization of produced o-Ps can be determined on the event by event basis in a direction of the positron motion. We intend to use 22Na or other beta+ decay isotopes as a source of polarized positrons. Due to the parity violation in the beta decay, the emitted positrons are longitudinally polarized. The choice of the quantization axis is based on the known position of the positron emitter and the reconstructed position of the positronium annihilation. We show that the J-PET tomography is equipped with all needed components.
Human Tissue Investigations Using PALS Technique - Free Radicals Influence
B. Jasińska, B. Zgardzińska, G. Chołubek, M. Pietrow, M. Gorgol, K. Wiktor, K. Wysogląd, P. Białas, C. Curceanu, E. Czerwiński, K. Dulski, A. Gajos, B. Głowacz, B.C. Hiesmayr, B. Jodłowska-Jędrych, D. Kamińska, G. Korcyl, P. Kowalski, T. Kozik, N. Krawczyk, W. Krzemień, E. Kubicz, M. Mohammed, M. Pawlik-Niedźwiecka, S. Niedźwiecki, M. Pałka, L. Raczyński, Z. Rudy, N.G. Sharma, S. Sharma, R. Shopa, M. Silarski, M. Skurzok, A. Wieczorek, H. Wiktor, W. Wiślicki, M. Zieliński, P. Moskal
abstract
The positron annihilation lifetime spectroscopy was applied to the samples of the human uterine leiomyomas and the normal myometrium tissues taken from the selected place of the uterus during a surgery. The method indicated differences in values of the measured positron annihilation lifetime spectroscopy parameters (lifetimes and intensities) between healthy and diseased tissue samples. The additional measurements were performed either in darkness or in presence of visible light which influenced the free radicals present in both kind of tissues and, as a result, made changes in free annihilation and o-Ps decay lifetime and intensity values.
Preliminary Studies of J-PET Detector Spatial Resolution
M. Pawlik-Niedźwiecka, S. Niedźwiecki, D. Alfs, P. Białas, C. Curceanu, E. Czerwiński, K. Dulski, A. Gajos, B. Głowacz, M. Gorgol, B. C. Hiesmayr, B. Jasińska, D. Kisielewska, G. Korcyl, P. Kowalski, T. Kozik, N. Krawczyk, W. Krzemień, E. Kubicz, M. Mohammed, M. Pałka, L. Raczyński, J. Raj, Z. Rudy, Shivani, M. Silarski, M. Skurzok, N.G. Sharma, S. Sharma, R.Y. Shopa, A. Strzelecki, A. Wieczorek, W. Wiślicki, B. Zgardzińska, M. Zieliński, P. Moskal
abstract
The J-PET detector, based on long plastic scintillator strips, was recently constructed at the Jagiellonian University. It consists of 192 modules axially arranged into three layers, read out from both sides by digital constant-threshold front-end electronics. This work presents preliminary results of measurements of the spatial resolution of the J-PET tomograph performed with 22Na source placed at selected position inside the detector chamber.
Emergence in Particle Physics
S.D. Bass
abstract
Hadron properties and interactions are emergent from QCD. Atomic and condensed matter physics are emergent from QED. Could the local gauge symmetries of particle physics also be emergent? We give an introduction to this question and recent ideas connecting it to the stability of the Standard Model Higgs vacuum and the value of the cosmological constant.
Underwater detection of dangerous substances: status of the SABAT project
M. Silarski, P. Sibczyński, Sz. Niedźwiecki, S. Sharma, J. Raj, P. Moskal
abstract
The Neutron Activation Analysis (NAA) plays an exceptional role in the modern nuclear engineering, especially in detection of hazardous substances. However, in the aquatic environment, there are still many problems to be solved for effective usage of this technique. We present the status of SABAT (Stoichiometry Analysis By Activation Techniques), one of the projects aiming at the construction of an underwater device for non-invasive threat detection based on the NAA.
Genuine Multipartite Entanglement in the 3-Photon Decay of Positronium
B.C. Hiesmayr, P. Moskal
abstract
Isoscalar single-pion production in the region of Roper and d*(2380) resonances
P. Adlarsona, W. Augustyniak, W. Bardan, M. Bashkanov, FS. Bergmann, M. Berlowski, H. Bhatt, A. Bondar, M. Buscher, H. Calen, I. Ciepal, H. Clement, E. Czerwinski, K. Demmich, R. Engels, A. Erven, W. Erven, W. Eyrich, P. Fedorets, K. Fohl, K. Fransson, F. Goldenbaum, A. Goswami, K. Grigoryev, CO. Gullstrom, L. Heijkenskjold, V. Hejny, N. Husken, L. Jarczyk, T. Johansson, B. Kamys, G. Kemmerling, G. Khatri, A. Khoukaz, O. Khreptak, DA. Kirillov, S. Kistryn, H. Kleines, B. Klos, W. Krzemien, P. Kulessa, A. Kupsc, A. Kuzmin, K. Lalwani, D. Lersch, B. Lorentz, A. Magiera, R. Maier, P. Marciniewski, B. Marianski, HP. Morsch, P. Moskal, H. Ohm, W. Parol, EP. del Rio, NM. Piskunov, D. Prasuhn, D. Pszczel, K. Pysz, A. Pyszniak, J. Ritman, A. Roy, Z. Rudy, O. Rundel, S. Sawant, S. Schadmand, I. Schatti-Ozerianska, T. Sefzick, et al.
abstract
Exclusive measurements of the quasi-free pn -> pp pi(-) and pp -> pp pi(0) reactions have been performed by means of pd collisions at T-p= 1.2 GeV using the WASA detector setup at COSY. Total and differential cross sections have been obtained covering the energy region T-p= 0.95-1.3 GeV (root s = 2.3-2.46 GeV), which includes the regions of triangle(1232), N*(1440) and d*(2380) resonance excitations. From these measurements the isoscalar single-pion production has been extracted, for which data existed so far only below T-p = 1 GeV. We observe a substantial increase of this cross section around 1 GeV, which can be related to the Roper resonance N*(1440), the strength of which shows up isolated from the triangle resonance in the isoscalar (N pi)(I=0) invariant-mass spectrum. No evidence for a decay of the dibaryon resonance d*(2380) into the isoscalar (NN pi)(I=0) channel is found. An upper limit of 180 mu b (90% CL.) corresponding to a branching ratio of 9% has been deduced. (c) 2017 The Author(s). Published by Elsevier B.V.
Analysis procedure of the positronium lifetime spectra for the J-PET detector
K. Dulski , B. Zgardzińska , P. Białas , C. Curceanu E. Czerwiński , A. Gajos , B. Głowacz , M. Gorgol , B. C. Hiesmayr , B. Jasińska , D. Kisielewska-Kamińska , G. Korcyl , P. Kowalski , T. Kozik , N. Krawczyk , W. Krzemień , E. Kubicz , M. Mohammed , M. Pawlik-Niedźwiecka, S. Niedźwiecki , M. Pałka , L. Raczyński , J. Raj , Z. Rudy , N. G. Sharma, S. Sharma, Shivani, R. Y. Shopa, M. Silarski , M. Skurzok , A. Wieczorek , W. Wiślicki , M. Zieliński , P. Moskal
abstract
Positron Annihilation Lifetime Spectroscopy (PALS) has shown to be a powerful tool to study the nanostructures of porous materials. Positron Emissions Tomography (PET) are devices allowing imaging of metabolic processes e.g. in human bodies. A newly developed device, the J-PET (Jagiellonian PET), will allow PALS in addition to imaging, thus combining both analyses providing new methods for physics and medicine. In this contribution we present a computer program that is compatible with the J-PET software. We compare its performance with the standard program LT 9.0 by using PALS data from hexane measurements at different temperatures. Our program is based on an iterative procedure, and our fits prove that it performs as good as LT 9.0.
Introduction of total variation regularization into filtered backprojection algorithm
L. Raczyński, W. Wiślicki, K. Klimaszewski, W. Krzemień, P. Kowalski, R. Shopa, P. Białas, C. Curceanu, E. Czerwiński, K. Dulski A. Gajos, B. Głowacz, M. Gorgol, B. Hiesmayr, B. Jasińska, D. Kisielewska-Kamińska, G. Korcyl, T. Kozik, N. Krawczyk, E. Kubicz, M. Mohammed, M. Pawlik-Niedźwiecka, S. Niedźwiecki, M. Pałka, Z. Rudy, N.G. Sharma, S. Sharma, M. Silarski, M. Skurzok, A. Wieczorek, B. Zgardzińska, M. Zieliński, P. Moskal
abstract
In this paper we extend the state-of-the-art filtered backprojection (FBP) method with application of the concept of Total Variation regularization. We compare the performance of the new algorithm with the most common form of regularizing in the FBP image reconstruction via apodizing functions. The methods are validated in terms of cross-correlation coefficient between reconstructed and real image of radioactive tracer distribution using standard Derenzo-type phantom. We demonstrate that the proposed approach results in higher cross-correlation values with respect
to the standard FBP method.
Time calibration of the J-PET detector
M. Skurzok, M. Silarski, D. Alfs, P. Bialas, Shivani, C. Curceanu , E. Czerwinski , K. Dulski , A. Gajos, B. G lowacz , M. Gorgol, B. C. Hiesmayr, B. Jasinska, D. Kisielewska, G. Korcyl, P. Kowalski, T. Kozik , N. Krawczyk, W. Krzemien, E. Kubicz , M. Mohammed, M. Pawlik-Niedzwiecka, S. Niedzwiecki, M. Palka, L. Raczynski , J. Raj, Z. Rudy, N. G. Sharma, S. Sharma , R. Y. Shopa , A. Wieczorek, W. Wislicki , B. Zgardzinska, M. Zielinski , P. Moskal
abstract
The Jagiellonian Positron Emission Tomograph (J-PET) project carried out in the Institute of Physics of the Jagiellonian University is focused on construction and tests of the first prototype of PET scanner for medical diagnostic which allows for the simultaneous 3D imaging of the whole human body using organic scintillators. The J-PET prototype consists of 192 scintillator strips forming three cylindrical layers which are optimized for the detection of photons from the electron-positron annihilation with high time- and high angular-resolutions. In this article we present time calibration and synchronization of the whole J-PET detection system by irradiating each single detection module with a 22Na source and a small detector providing common reference time for synchronization of all the modules.
Novel scintillating material 2-(4-styrylphenyl)benzoxazole for the fully digital and MRI compatible J-PET tomograph based on plastic scintillators
A. Wieczorek, K. Dulski, Sz. Niedźwiecki, D. Alfs, P. Białas, C. Curceanu, E. Czerwiński, A. Danel, A. Gajos, B. Głowacz, M. Gorgol, B. Hiesmayr, B. Jasińska, K. Kacprzak, D. Kamińska, Ł. Kapłon, A. Kochanowski, G. Korcyl, P. Kowalski, T. Kozik, W. Krzemień, E. Kubicz, M. Kucharek, M. Mohammed, M. Pawlik-Niedźwiecka, M. Pałka, L. Raczyński, Z. Rudy, O. Rundel, N. G. Sharma, M. Silarski, T. Uchacz, W. Wiślicki, B. Zgardzińska, M. Zieliński, P. Moskal
abstract
A novel
plastic
scintillator
is developed
for
the
application
in the
digital
positron
emission
tomography
(PET).
The
novelty
of the
concept
lies
in application
of the
2-(4-styrylphenyl)
benzoxazole
as
a wavelength
shifter.
The
substance
has
not
been
used
as
scintillator
dop-
ant
before.
A dopant
shifts
the
scintillation
spectrum
towards
longer
wavelengths
making
it
more
suitable
for
applications
in scintillators
of long
strips
geometry
and
light
detection
with
digital
silicon
photomultipliers.
These
features
open
perspectives
for
the
construction
of the
cost-effective
and
MRI-compatib
le PET
scanner
with
the
large
field
of view.
In this
article
we
present
the
synthesis
method
and
characterize
performance
of the
elaborated
scintillator
by
determining
its
light
emission
spectrum,
light
emission
efficiency,
rising
and
decay
time
of
the
scintillation
pulses
and
resulting
timing
resolution
when
applied
in the
positron
emission
tomography.
The
optimal
concentratio
n of the
novel
wavelength
shifter
was
established
by
maximizing
the
light
output
and
it was
found
to be
0.05
?
for
cuboidal
scintillator
with
dimen-
sions
of 14
mm
x 14
mm
x 20
mm.
Low-energy Antikaon-Nucleon/Nuclei Interaction Studies by AMADEUS
K. Piscicchia, M. Cargnelli, C. Curceanu, R. Del Grande, L. Fabbietti, C. Guaraldo, J. Marton, P. Moskal, A. Scordo, M. Silarski, D. Sirghi, M. Skurzok, I. Tucakovic, O. Vazquez Doce, S. Wycech, E. Widmann, J. Zmeskal
abstract
The AMADEUS experiment deals with the investigation of the low-energy kaon?nuclei hadronic interaction at the DA?NE collider at LNF-INFN, which is fundamental to solve longstanding questions in the non-perturbative strangeness QCD sector. AMADEUS step 0 consisted in the reanalysis of the 2004/2005 KLOE data, exploiting K- absorptions in H, 4He, 9Be and 12C, leading to the first invariant mass spectroscopy study with very low-momentum (100 MeV) in-flight K? captures. With AMADEUS step 1, a dedicated pure carbon target was implemented in the central region of the KLOE detector, providing a high statistic sample of pure at-rest K? nuclear interaction. The results obtained in the analyses of the hyperon?pion correlated events, searching for the resonant shapes of Y states, will be described.
Commissioning of the J-PET Detector for Studies of Decays of Positronium Atoms
E. Czerwiński, K. Dulski, P. Białas, C. Curceanu, A. Gajos, B. Głowacz, M. Gorgol, B.C. Hiesmayr, B. Jasińska, D. Kisielewska, G. Korcyl, P. Kowalski, T. Kozik, N. Krawczyk, W. Krzemień, E. Kubicz, M. Mohammed, Sz. Niedźwiecki, M. Pałka, M. Pawlik-Niedźwiecka, L. Raczyński, Z. Rudy, N.G. Sharma, S. Sharma, R.Y. Shopa, M. Silarski, M. Skurzok, A. Wieczorek, W. Wiślicki, B. Zgardzińska, M. Zieliński, P. Moskal
abstract
The Jagiellonian Positron Emission Tomograph (J-PET) is a detector for medical imaging of the whole human body as well as for physics studies involving detection of electron?positron annihilation into photons. J-PET has high angular and time resolution, and allows for measurement of spin of the positronium and the momenta and polarization vectors of annihilation quanta. In this article, we present the potential of the J-PET system for the background rejection in the decays of positronium atoms.
A New PET Diagnostic Indicator Based on the Ratio of 3gamma/2gamma Positron Annihilation
B. Jasińska, P. Moskal
abstract
The idea of applying the ratio of 3g and 2g positron annihilation rate as a diagnostic indicator in the PET imaging is proposed. It is based on the fact that the 3g annihilation is related to the decay rate of triplet state of positronium atoms produced inside the human body during the PET imaging, and it reflects the size and the concentration of free volumes present in the investigated tissues. The tissues deformation related to the cancerous changes are expected to influence the local value of the 3g fraction.
Search for the eta-mesic Helium in Proton-Deuteron Reaction
O. Rundel, M. Skurzok, O. Khreptak, P. Moskal
abstract
We briefly report on the search for eta-mesic helium nuclei with WASA-at-COSY detection setup. The description of the experimental method as well as the status of the data analysis of the proton?deuteron reactions are presented.
J-PET: A New Technology for the Whole-body PET Imaging
S. Niedźwiecki, P. Białas, C. Curceanu, E. Czerwiński, K. Dulski, A. Gajos, B. Głowacz, M. Gorgol, B.C. Hiesmayr, B. Jasińska, Ł. Kapłon, D. Kisielewska-Kamińska, G. Korcyl, P. Kowalski, T. Kozik, N. Krawczyk, W. Krzemień, E. Kubicz, M. Mohammed, M. Pawlik-Niedźwiecka, M. Pałka, L. Raczyński, Z. Rudy, N.G. Sharma, S. Sharma, R.Y. Shopa, M. Silarski, M. Skurzok, A. Wieczorek, W. Wiślicki, B. Zgardzińska, M. Zieliński, P. Moskal
abstract
The Jagiellonian Positron Emission Tomograph (J-PET) is the first PET built from plastic scintillators. J-PET prototype consists of 192 detection modules arranged axially in three layers forming a cylindrical diagnostic chamber with the inner diameter of 85 cm and the axial field-of-view of 50 cm. An axial arrangement of long strips of plastic scintillators, their small light attenuation, superior timing properties, and relative ease of the increase of the axial field-of-view opens promising perspectives for the cost effective construction of the whole-body PET scanner, as well as construction of MR and CT compatible PET inserts. Present status of the development of the J-PET tomograph will be presented and discussed.
The pd -> eta 3He Reaction and eta 3He Bound State? The B*B*rho System
E. Oset, J.J. Xie, W.H. Liang, P. Moskal, M. Skurzok, C. Wilkin, M. Bayar, P. Fernandez Soler, Z.F. Sun
abstract
We analyze the data on cross sections and asymmetries for the pd(dp) -> eta 3He reaction close to threshold and look for bound states of the eta 3He system. Fitting these data in terms of an eta 3He optical potential, we find a local Breit?Wigner form of the eta 3He amplitude T below threshold with a clear peak in |T|2, which corresponds to an eta 3He binding of about 0.3 MeV and a width of about 3 MeV. However, this corresponds to a pole in the complex plane above threshold. We also discuss a state found for BB*rho with J = 3.
Three-dimensional Image Reconstruction in J-PET Using Filtered Back-projection Method
R.Y. Shopa, K. Klimaszewski, P. Kowalski, W. Krzemień, L. Raczyński, W. Wiślicki, P. Białas, C. Curceanu, E. Czerwiński, K. Dulski, A. Gajos, B. Głowacz, M. Gorgol, B. Hiesmayr, B. Jasińska, D. Kisielewska-Kamińska, G. Korcyl, T. Kozik, N. Krawczyk, E. Kubicz, M. Mohammed, M. Pawlik-Niedźwiecka, S. Niedźwiecki, M. Pałka, Z. Rudy, N.G. Sharma, S. Sharma, M. Silarski, M. Skurzok, A. Wieczorek, B. Zgardzińska, M. Zieliński, P. Moskal
abstract
We present a method and preliminary results of the image reconstruction in the Jagiellonian PET tomograph. Using GATE (Geant4 Application for Tomographic Emission), interactions of the 511 keV photons with a cylindrical detector were generated. Pairs of such photons, flying back-to-back, originate from e+e? annihilations inside a 1 mm spherical source. Spatial and temporal coordinates of hits were smeared using experimental resolutions of the detector. We incorporated the algorithm of the 3D Filtered Back Projection, implemented in the STIR and TomoPy software packages, which differ in approximation methods. Consistent results for the Point Spread Functions of ? 5 ÷ 7 mm and ? 9 ÷ 20 mm were obtained, using STIR, for transverse and longitudinal directions, respectively, with no time-of-flight information included.
Low-energy Kaon-Nuclei Interaction Studies at DAFNE: SIDDHARTA-2 and AMADEUS
C. Curceanu, A. Amirkhani, M. Bazzi, G. Bellotti, C. Berucci, D. Bosnar, A.M. Bragadireanu, M. Cargnelli, A. Dawood Butt, R. Del Grande, L. Fabbietti, C. Fiorini, F. Ghio, C. Guaraldo, R.S. Hayano, M. Iliescu, M. Iwasaki, P. Levi Sandri, J. Marton, M. Miliucci, P. Moskal, D. Pietreanu, K. Piscicchia, A. Scordo, H. Shi, M. Silarski, D. Sirghi, F. Sirghi, M. Skurzok, H. Tatsuno, O. Vazquez Doce, E. Widmann, J. Zmeskal
abstract
The DAFNE electron?positron collider of the Laboratori Nazionali di Frascati of INFN has made available a unique quality low-energy negatively charged kaons ?beam?, which is being used to study the kaon?nucleon/nuclei interactions by the SIDDHARTA-2 experiment and the AMADEUS Collaboration. The dynamics of the strong interaction processes in the non-perturbative regime is approached by lattice calculations and effective field theories (ChPT) which are still lacking experimental results in the low-energy regime, fundamental for their good understanding. The studies of kaonic atoms and of the kaonic nuclear processes performed by SIDDHARTA-2 and AMADEUS play in this context a key-role.
Drift Chamber Calibration and Track Reconstruction in the P349 Antiproton Polarization Experiment
D. Alfs, B. Głowacz, P. Moskal, M. Zieliński, D. Grzonka, F. Hauenstein, K. Kilian, D. Lersch, J. Ritman, T. Sefzick, W. Oelert, M. Diermaier, E. Widmann, J. Zmeskal, M. Wolke, P. Nadel-Turonski, M. Carmignotto, T. Horn, H. Mkrtchyan, A. Asaturyan, A. Mkrtchyan, V. Tadevosyan, S. Zhamkochyan, S. Malbrunot-Ettenauer, W. Eyrich
abstract
The goal of the P349 experiment is to test whether the antiproton production process can be itself a source of antiproton polarization. In this article, we present the motivation and details of the performed measurement. We report on the status of the analysis focusing mainly on calibration of the drift chambers and 3d track reconstruction.
Human Tissues Investigation Using PALS Technique
B. Jasińska, B. Zgardzińska, G. Chołubek, M. Gorgol, K. Wiktor, K. Wysogląd, P. Białas, C. Curceanu, E. Czerwiński, K. Dulski, A. Gajos, B. Głowacz, B. Hiesmayr, B. Jodłowska-Jędrych, D. Kamińska, G. Korcyl, P. Kowalski, T. Kozik, N. Krawczyk, W. Krzemień, E. Kubicz, M. Mohammed, M. Pawlik-Niedźwiecka, S. Niedźwiecki, M. Pałka, L. Raczyński, Z. Rudy, N.G. Sharma, S. Sharma, R. Shopa, M. Silarski, M. Skurzok, A. Wieczorek, H. Wiktor, W. Wiślicki, M. Zieliński, P. Moskal
abstract
Samples of uterine leiomyomatis and normal tissues taken from patients after surgery were investigated using the Positron Annihilation Lifetime Spectroscopy (PALS). Significant differences in all PALS parameters between normal and diseased tissues were observed. For all studied patients, it was found that the values of the free annihilation and ortho-positronium lifetime are larger for the tumorous tissues than for the healthy ones. For most of the patients, the intensity of the free annihilation and ortho-positronium annihilation was smaller for the tumorous than for the healthy tissues. For the first time, in this kind of studies, the 3? fraction of positron annihilation was determined to describe changes in the tissue porosity during morphologic alteration.
Light neutral CP-even Higgs boson within the next-to-minimal supersymmetric standard model at the Large Hadron Electron Collider
Siba Prasad Das and Marek Nowakowski
abstract
We analyze the prospects of observing the light charge parity (CP)-even neutral Higgs bosons (h1) in their decays into bb? quarks, in the neutral and charged current production processes eh1q and ?h1q at the upcoming Large Hadron Electron Collider (LHeC), with sqrt(s) = 1.296 TeV. Assuming that the intermediate Higgs boson (h2) is Standard Model (SM)-like, we study the Higgs production within the framework of next-to-minimal supersymmetric Standard Model (NMSSM). We consider the constraints from darkmatter, sparticle masses, and the Higgs boson data. The signal in our analysis can be classified as three jets, with electron (missing energy) coming from the neutral (charged) current interaction. We demand that the number of b-tagged jets in the central rapidity region be greater or equal to two. The remaining jet is tagged in the forward regions. With this forward jet and two b-tagged jets in the central region, we reconstructed three jets invariant masses. Applying some lower limits on these invariant masses turns out to be an
essential criterion to enhance the signal?to?background rates, with slightly different sets of kinematical selections in the two different channels. We consider almost all reducible and irreducible SM background processes. We find that the non-SM like Higgs boson, h1, would be accessible in some of the NMSSM benchmark points, at approximately the 0.4? (2.5?) level in the Et 3j channel up to Higgs boson masses of 75 GeV, and in the ET + 3j channel could be discovered with the 1.7? (2.4?) level up to Higgs boson
masses of 88 GeV with 100 fb^?1 of data in a simple cut-based (with optimization) selection. With ten times more data accumulation at the end of the LHeC run, and using optimization, one can have 5? discovery in the electron (missing energy) channel up to 85 (more than 90) GeV.
Human Tissues Investigation Using PALS Technique
B. Jasińska, B. Zgardzińska, G. Chołubek, M. Gorgol, K. Wiktor, K. Wysogląd, P. Białas, C. Curceanu, E. Czerwiński, K. Dulski, A. Gajos, B. Głowacz, B.C. Hiesmayr, B. Jodłowska-Jędrych, D. Kamińska, G. Korcyl, P. Kowalski, T. Kozik, N. Krawczyk, W. Krzemień, E. Kubicz, M. Mohammed, M. Pawlik-Niedźwiecka, S. Niedźwiecki, M. Pałka, L. Raczyński, Z. Rudy, N.G. Sharma, S. Sharma, R. Shopa, M. Silarski, M. Skurzok, A. Wieczorek, H. Wiktor, W. Wiślicki, M. Zieliński, P. Moskal
abstract
Samples of uterine leiomyomatis and normal tissues taken from patients
after surgery were investigated using the Positron Annihilation Lifetime
Spectroscopy (PALS). Significant differences in all PALS parameters
between normal and diseased tissues were observed. For all studied patients,
it was found that the values of the free annihilation and orthopositronium
lifetime are larger for the tumorous tissues than for the healthy
ones. For most of the patients, the intensity of the free annihilation and
ortho-positronium annihilation was smaller for the tumorous than for the
healthy tissues. For the first time, in this kind of studies, the 3gamma fraction
of positron annihilation was determined to describe changes in the tissue
porosity during morphologic alteration.
Tests of discrete symmetries and quantum coherence with neutral kaons at the KLOE-2 experiment
A. Gajos
abstract
The KLOE-2 detector records decays of quantum-entangled pairs of neutral kaons produced in decays of ? mesons provided by the DA?NE accelerator at the Laboratori Nazionali di Frascati, Italy. This system allows for a broad range of studies of fundamental discrete symmetries including tests which are only feasible with entangled neutral mesons. This work reports on the Lorentz non-invariance and CPT violation searches with the ? ? KSKL ? ?+???+?? process in the framework of the Standard Model Extension. Moreover, status and results of quantum coherence tests with the same process are discussed. Finally, the status of ongoing direct tests of T and CPT in neutral kaon transitions is presented. For each of the reported studies, perspectives are discussed for the KLOE-2 experiment, which is presently taking data.
Multichannel FPGA based MVT system for high precision time (20 ps RMS) and charge measurement
M. Palka, P. Strzempek, G. Korcyl, T. Bednarski, S. Niedzwiecki, P. Bialas, E. Czerwinski, K. Dulski, A. Gajos, B. Glowacz, M. Gorgol, B. Jasinska, D. Kaminska, M. Kajetanowicz, P. Kowalski, T. Kozik, W. Krzemien, E. Kubicz, M. Mohhamed, L. Raczynski, Z. Rudy, O. Rundel, P. Salabura, NG. Sharma, M. Silarski, J. Smyrski, A. Strzelecki, A. Wieczorek, W. Wislicki, M. Zielinski, B. Zgardzinska, P. Moskal
abstract
In this article it is presented an FPGA based Multi-Voltage Threshold (MVT) system which allows of sampling fast signals (1-2 ns rising and falling edge) in both voltage and time domain. It is possible to achieve a precision of time measurement of 20 ps RMS and reconstruct charge of signals, using a simple approach, with deviation from real value smaller than 10%. Utilization of the differential inputs of an FPGA chip as comparators together with an implementation of a TDC inside an FPGA allowed us to achieve a compact multi-channel system characterized by low power consumption and low production costs. This paper describes realization and functioning of the system comprising 192-channel TDC board and a four mezzanine cards which split incoming signals and discriminate them. The boards have been used to validate a newly developed Time-of-Flight Positron Emission Tomography system based on plastic scintillators. The achieved full system time resolution of sigma (TOF) approximate to 68 ps is by factor of two better with respect to the current TOF-PET systems.
Ranking and validation of spallation models for isotopic production cross sections of heavy residua
S. Sharma, B. Kamys, F. Goldenbaum, D. Filges
abstract
The production cross sections of isotopically identified residual nuclei of spallation reactions induced by 136Xe projectiles at 500 AMeV on hydrogen target were analyzed in a two-step model. The first stage of the reaction was described by the INCL4.6 model of an intranuclear cascade of nucleon-nucleon and pion-nucleon collisions whereas the second stage was analyzed by means of four different models; ABLA07, GEM2, GEMINI++ and SMM. The quality of the data description was judged quantitatively using two statistical deviation factors; the H-factor and the M-factor. It was found that the present analysis leads to a different ranking of models as compared to that obtained from the qualitative inspection of the data reproduction. The disagreement was caused by sensitivity of the deviation factors to large statistical errors present in some of the data. A new deviation factor, the A factor, was proposed, that is not sensitive to the statistical errors of the cross-sections. The quantitative ranking of models performed using the A-factor agreed well with the qualitative analysis of the data. It was concluded that using the deviation factors weighted by statistical errors may lead to erroneous conclusions in the case when the data cover a large range of values. The quality of data reproduction by the theoretical models is discussed. Some systematic deviations of the theoretical predictions from the experimental results are observed.
The cylindrical GEM detector of the KLOE-2 experiment
G. Bencivenni, P. Branchini, P. Ciambrone, E. Czerwinski, E. De Lucia, A. Di Cicco D. Domenici, G. Felici, P. Fermani and G. Morello
abstract
The KLOE-2 experiment started its data taking campaign in November 2014 with an upgraded tracking system at the DA?NE electron-positron collider at the Frascati National Laboratory of INFN. The new tracking device, the Inner Tracker, operated together with the KLOE-2 Drift Chamber, has been installed to improve track and vertex reconstruction capabilities of the experimental apparatus. The Inner Tracker is a cylindrical GEM detector composed of four cylindrical triple-GEM detectors, each provided with an X-V strips-pads stereo readout. Although GEM detectors are already used in high energy physics experiments, this device is considered a frontier detector due to its fully-cylindrical geometry: KLOE-2 is the first experiment benefiting of this novel detector technology. Alignment and calibration of this detector will be presented together with its operating performance and reconstruction capabilities.
Measurement of the omega->pi+pi-pi0 Dalitz plot distribution
P. Adlarson, ..., E. Czerwiński, O. Khreptak, W. Krzemień, P. Moskal, O. Rundel, I. Schätti-Ozerianska, M. Skurzok, M.J. Zieliński, et al.
abstract
Using the production reactions pd->3Heomega and pp->pp omega, the Dalitz plot distribution for the omega->pi+pi-pi0 decay is studied with the WASA detector at COSY, based on a combined data sample of (4.408+-0.042)*10^4 events. The Dalitz plot density is parametrised by a product of the P-wave phase space and a polynomial expansion in the normalised polar Dalitz plot variables Z and phi. For the first time, a deviation from pure P-wave phase space is observed with a significance of 4.1 sigma. The deviation is parametrised by a linear term 1+2 alpha Z, with alpha determined to be +0.147+-0.036, consistent with the expectations of rho-meson-type final-state interactions of the P-wave pion pairs.
Calculation of the time resolution of the J-PET tomograph using kernel density estimation
L. Raczyński, W. Wiślicki, W. Krzemień, P. Kowalski, D. Alfs, T. Bednarski, P. Białas, C. Curceanu, E. Czerwiński, K. Dulski, A. Gajos, B. Głowacz, M. Gorgol, B. Hiesmayr, B. Jasińska, D. Kamińska, G. Korcyl, T. Kozik, N. Krawczyk, E. Kubicz, M. Mohammed, M. Pawlik-Niedźwiecka, S. Niedźwiecki, M. Pałka, Z. Rudy, O. Rundel, N. Gupta-Sharma, M. Silarski, J. Smyrski, A. Strzelecki, A. Wieczorek, B. Zgardzińska, M. Zieliński and P. Moskal
abstract
In this paper we estimate the time resolution of the J-PET scanner built from plastic scintillators. We incorporate the method of signal processing using the Tikhonov regularization framework and the kernel density estimation method. We obtain simple, closed-form analytical formulae for time resolution. The proposed method is validated using signals registered by means of the single detection unit of the J-PET tomograph built from a 30?cm long plastic scintillator strip. It is shown that the experimental and theoretical results obtained for the J-PET scanner equipped with vacuum tube photomultipliers are consistent.
Recent results and perspectives with KLOE-2
E. Czerwiński for the KLOE-2 Collaboration
abstract
In this paper we summarize the recent experimental results from KLOE-2 on the dark photon search in the e+e??U? , U??+?? , measurement of Branching Ratio and Transition Form Factor of ???0e+e? decay, Dalitz plot analysis of ???+???0 process and CPT symmetry and Lorentz invariance test with entangled K mesons. Additionally a discussion about ongoing test of CPT symmetry via measurement of K S charge asymmetry is included together with description of the KLOE-2 detection system.
Measurement of gamma quantum interaction point in plastic scintillator with WLS strips
J. Smyrski, D. Alfs, T. Bednarski, P. Białas, E. Czerwiński, K. Dulski, A. Gajos, B. Głowacz, N. Gupta-Sharma, M. Gorgol, B. Jasińska, M. Kajetanowicz, D. Kamińska, G. Korcyl, P. Kowalski, W. Krzemień, N. Krawczyk, E. Kubicz, M. Mohammed, Sz. Niedźwiecki, M. Pawlik-Niedźwiecka, L. Raczyński, Z. Rudy, P. Salabura, M. Silarski, A. Strzelecki, A. Wieczorek, W. Wiślicki, J. Wojnarska, B. Zgardzińska, M. Zieliński, P. Moskal
abstract
The feasibility of measuring the aśxial coordinate of a gamma quantum interaction point in a plastic scintillator
bar via the detection of scintillation photons escaping from the scintillator with an array of wavelength-shifting
(WLS) strips is demonstrated. Using a test set-up comprising a BC-420 scintillator bar and an array of sixteen
BC-482A WLS strips we achieved a spatial resolution of 5 mm (?) for annihilation photons from a 22Na isotope.
The studied method can be used to improve the spatial resolution of a plastic-scintillator-based PET scanner
which is being developed by the J-PET collaboration.
Technical Design Report for the Panda Forward Spectrometer Calorimeter
B. Singh, ..., P. Moskal, et al. (PANDA Collaboration)
abstract
This document is devoted to the electromagnetic calorimeter of the Forward Spectrometer and describes the design considerations, the technical layout, the expected performance, and the production readiness.
Spinning Gluons in the Proton
S.D. Bass
abstract
Computer simulations indicate that about 50% of the proton?s spin comes from the spin of the gluons that bind its quark constituents.
Feasibility study for the measurement of piN transition distribution amplitudes at PANDA in vec{p}p->J/psi pi0
B. Singh, W. Erni, B. Krusche, M. Steinacher, N. Walford, H. Liu, Z. Liu, B. Liu, X. Shen, C. Wang, J. Zhao, M. Albrecht, T. Erlen, M. Fink, FH. Heinsius, T. Held, T. Holtmann, S. Jasper, I. Keshk, H. Koch, B. Kopf, M. Kuhlmann, M. Kummel, S. Leiber, M. Mikirtychyants, P. Musiol, A. Mustafa, M. Pelizaeus, J. Pychy, M. Richter, C. Schnier, T. Schroder, C. Sowa, M. Steinke, T. Triffterer, U. Wiedner, M. Ball, R. Beck, C. Hammann, B. Ketzer, M. Kube, P. Mahlberg, M. Rossbach, C. Schmidt, R. Schmitz, U. Thoma, M. Urban, D. Walther, C. Wendel, A. Wilson, A. Bianconi, M. Bragadireanu, M. Caprini, D. Pantea, B. Patel, W. Czyzycki, M. Domagala, G. Filo, J. Jaworowski, M. Krawczyk, E. Lisowski, F. Lisowski, M. Michalek, P. Poznanski, J. Plazek, K. Korcyl, A. Kozela, P. Kulessa, P. Lebiedowicz, K. Pysz, W. Schaefer, et al.
abstract
The exclusive charmonium production process in p?p annihilation with an associated pi0 meson vec{p}p ->J=psi pi 0 is studied in the framework of QCD collinear factorization. The feasibility of measuring this reaction through the J=psi -> e+e- decay channel with the AntiProton ANnihilation at DArmstadt (PANDA) experiment is investigated. Simulations on signal reconstruction efficiency as well as the background rejection from various sources including the vec{p}p -> pi+pi-pi0 and vec{p} -> J=psi pi0 pi0 reactions are performed with PANDA ROOT , the simulation and analysis software framework of the PANDA experiment. It is shown that the measurement can be done at P?ANDA with significant constraining power under the assumption of an integrated luminosity attainable in four to five months of data taking at the maximum design luminosity.
The KLOE-2 Inner Tracker: Detector commissioning and operation
A. Balla, G. Bencivenni, P. Branchini, P. Ciambrone, E. Czerwinski, E. De Lucia, A. Cicco, D. Di Domenici, G. Felici, G. Morello
abstract
The KLOE-2 experiment started its data taking campaign in November 2014 with an upgraded tracking system including an Inner Tracker built with the cylindrical GEM technology, to operate together with the Drift Chamber improving the apparatus tracking performance. The Inner Tracker is composed of four cylindrical triple-GEM, each provided with an X?V strips-pads stereo readout and equipped with the GASTONE ASIC developed inside the KLOE-2 collaboration. Although GEM detectors are already used in high energy physics experiment, this device is considered a frontier detector due to its cylindrical geometry: KLOE-2 is the first experiment to use this novel solution. The results of the detector commissioning, detection efficiency evaluation, calibration studies and alignment, both with dedicated cosmic-ray muon and Bhabha scattering events, will be reported.
Search for eta-mesic 4He in the dd->3He n pi0 and dd->3He p pi- reactions with the WASA-at-COSY facility
P. Adlarson, ..., E. Czerwiński, O. Khreptak, W. Krzemień, P. Moskal, O. Rundel, I. Schätti-Ozerianska, M. Skurzok, M.J. Zieliński, et al.
abstract
The search for 4He-eta bound states was performed with the WASA-at-COSY facility via the measurement of the excitation function for the dd->3Henpi0 and dd->3Hepi- processes. The deuteron beam momentum was varied continuously between 2.127 GeV/c and 2.422 GeV/c, corresponding to the excess energy for the dd-> 4He eta reaction ranging from Q = -70 MeV to Q = 30 MeV. The luminosity was determined based on the dd-> 3Hen reaction and the quasi-free proton-proton scattering via dd -> ppn_spectator n_spectator reactions. The excitation functions, determined independently for the measured reactions, do not reveal a structure which could be interpreted as a narrow mesic nucleus. Therefore, the upper limits of the total cross sections for the bound state production and decay in dd->(4He-eta)bound->3Henpi0 and dd->(4He-eta)bound->3Hepi- processes were determined taking into account the isospin relation between the both of the considered channels. The results of the analysis depend on the assumptions of the N*(1535) momentum distribution in the anticipated mesic-4He. Assuming, as in the previous works, that this is identical with the distribution of nucleons bound with 20 MeV in 4He, we determined that (for the mesic bound state width in the range
from 5 MeV to 50 MeV) the upper limits at 90% confidence level are about 3 nb and about 6 nb for npi0 and p pi- channels, respectively. However, based on the recent theoretical findings of the N*(1535) momentum distribution in the N* -3He nucleus bound by 3.6 MeV, we find that the WASA-at-COSY detector acceptance decreases and hence the corresponding upper limits are 5 nb and 10 nb for n pi0 and p pi- channels respectively.
Determination of the eta 3He threshold structure from the low energy pd -> eta 3He reaction
J.-J. Xie, W.-H. Liang, E. Oset, P. Moskal, M. Skurzok and C. Wilkin
abstract
We analyze the data on cross sections and asymmetries for the pd(dp) -> eta 3He reaction close to threshold and look for bound states of the eta 3He system. Rather than parameterizing the scattering matrix, as is usually done, we develop a framework in which the eta 3He optical potential is the key ingredient, and its strength, together with some production parameters, are fitted to the available experimental data. The relationship of the scattering matrix to the optical potential is established using the Bethe-Salpeter equation and the eta 3He loop function incorporates the range of the interaction given by the empirical 3He density. We find a local Breit Wigner form of the eta 3He amplitude T
below threshold with a clear peak in |T|^2 , which corresponds to an eta binding of about 0.3 MeV and a width of about 3 MeV. By fitting the potential we can also evaluate the eta 3He scattering length, including its sign, thus resolving the ambiguity in the former analyses.
Determination of the spin triplet p Lambda scattering length from the final state interaction in the vec(p)p -> pK +Lambda reaction
F. Hauenstein, ..., P. Moskal, et al.
abstract
The vec(p)p?pK+Lambda reaction has been measured with the COSY-TOF detector at a beam momentum of 2.7GeV/c. The polarized proton beam enables the measurement of the beam analyzing power by the asymmetry of the produced kaon (AKN). This observable allows the pLambda spin triplet scattering length to be extracted for the first time model independently from the final state interaction in the reaction. The obtained value is at=(?2.55+0.72?1.39stat.+-0.6syst.+-0.3theo.)fm. This value is compatible with theoretical predictions and results from model-dependent analyses.
Measurements of branching ratios for eta decays into charged particles
P. AdlarsoN, W. Augustyniak, W. Bardan, M. Bashkanov, FS. Bergmann, M. Berlowski, H. Bhatt, A. Bondar, M. Buscher, H. Calen, I. Ciepal, H. Clement, D. Coderre, E. Czerwinski, K. Demmich, R. Engels, A. Erven, W. Erven, W. Eyrich, P. Fedorets, K. Fohl, K. Fransson, F. Goldenbaum, A. Goswami, K. Grigoryev, CO. Gullstrom, L. Heijkenskjold, V. Hejny, N. Husken, L. Jarczyk, T. Johansson, B. Kamys, G. Kemmerling, FA. Khan, G. Khatri, A. Khoukaz, DA. Kirillov, S. Kistryn, H. Kleines, B. Klos, W. Krzemien, P. Kulessa, A. Kupsc, A. Kuzmin, K. Lalwani, D. Lersch, B. Lorentz, A. Magiera, R. Maier, P. Marciniewski, B. Marianski, M. Mikirtychiants, HP. Morsch, P. Moskal, H. Ohm, I. Ozerianska, EP. del Rio, NM. Piskunov, D. Prasuhn, D. Pszczel, K. Pysz, A. Pyszniak, J. Ritman, A. Roy, Z. Rudy, O. Rundel, S. Sawant, S. Schadmand, et al.
abstract
The WASA-at-COSY experiment has collected 3 x 10(7) events with eta mesons produced via the reaction pd -> He-3 eta at T = 1.0 GeV. Using this data set, we evaluate the branching ratios of the decays eta -> pi(+)pi(-)gamma, eta -> e(+)e(-)gamma, eta -> pi(+)pi(-)e(+)e(-), and eta -> e(+)e(-)e(+)e(-). The branching ratios are normalized to the eta -> pi(+)pi(-) pi(0) decay. In addition an upper limit on a CP-violating asymmetry in eta -> pi(+)pi(-)e(+)e(-) is extracted.
Measurement of the running of the fine structure constant below 1 GeV with the KLOE detector
KLOE-2 Collaboration: A. Anastasi, E. Czerwiński, A. Gajos, D. Kamińska, W. Krzemień, P. Moskal, M. Silarski, W. Wiślicki, et al.
abstract
We have measured the running of the effective QED coupling constant alpha(s) in the time-like region 0.6
J-PET: A Novel TOF -PET scanner using Organic Scintillators
N.G. Sharma, M. Silarski, D. Alfs, T. Bednarski, P. Białas, E. Czerwiński, K. Dulski, A. Gajos, B. Głowacz, M. Gorgol, B. Jasińska, D. Kamińska, G. Korcyl, P. Kowalski, W. Krzemień, N. Krawczyk, E. Kubicz, M. Mohammed, Sz. Niedźwiecki, M. Pawlik-Niedźwiecka, L. Raczyński, Z. Rudy, O. Rundel, A. Wieczorek, W. Wislicki, M. Zieliński, B. Zgardzińska, P. Moskal
abstract
Positron Emission Tomography (PET) is one of the most advanced nuclear medicine imaging techniques that
have potential to identify many diseases (like cancers, heart diseases, neurological disorders and other abnormalities) in vivo in the earliest stages. However, production of PET modalities for covering the whole human body is economically unrealistic when applying the current technologies. In order to achieve a goal of more economical PET scanner with large geometrical acceptance and improved time resolution, the Jagiellonian Positron Emission Tomography (J-PET) Collaboration is realizing a new project aiming at construction of TOF-PET detector using plastic scintillators instead of crystals. Novelty of the J-PET scanner lies in: (i) application of plastic scintillators as well as in (ii) its front-end electronics which allows signal sampling in voltage domain, (iii) a trigger-less data acquisition system, and (iv) the new time and hit-position reconstruction methods. Moreover, the proposed solution enables to increase the axial field-of-view of the tomograph by extending the length of the plastic scintillator strips without changing the number of photomultipliers and electronic channels.
Feasibility studies of time-like proton electromagnetic form factors at PANDA at FAIR
B. Singh, ..., P. Moskal, et al. (PANDA Collaboration)
abstract
Simulation results for future measurements of electromagnetic proton form factors at PANDA
(FAIR) within the PandaRoot software framework are reported. The statistical precision with which the proton form factors can be determined is estimated. The signal channel vec{p}p -> e+ e- is studied on the basis of two different but consistent procedures. The suppression of the main background channel, i.e. vec{p}p -> pi+ pi-, is studied. Furthermore, the background versus signal efficiency, statistical and systematical uncertainties on the extracted proton form factors are evaluated using two different procedures. The results are consistent with those of a previous simulation study using an older, simplified framework. However, a slightly better precision is achieved in the PandaRoot study in a large range of momentum transfer, assuming the nominal beam conditions and detector performance.
Measurement of polarization observables of the associated strangeness production in proton proton interactions
F. Hauenstein, E. Borodina, H. Clement, E. Doroshkevich, R. Dzhygadlo, K. Ehrhardt, W. Eyrich, W. Gast, A. Gillitzer, D. Grzonka, S. Jowzaee, P. Klaja, L. Kober, K. Kilian, M. Krapp, M. Mertens, P. Moskal, J. Ritman, E. Roderburg, M. Roder, W. Schroeder, T. Sefzick, J. Smyrski, P. Wintz, P. Wustner
abstract
The Lambda polarization, the analyzing power, and the Lambda spin transfer coefficient of the reaction pp -> pK(+) Lambda were measured at beam momenta of 2.70 GeV/c and 2.95 GeV/c corresponding to excess energies of 122MeV and 204MeV. While the analyzing power and the spin transfer coefficient do not change significantly with the excess energy, the Lambda polarization varies strongly and changes its sign. As this is the first measurement of polarization observables below an excess energy of 200MeV, the change of the sign of the Lambda polarization was not observed before. The high statistics of the data (approximate to 200 k events for each momentum) enables detailed studies of the dependence of the Lambda polarization and the analyzing power on the center-of-mass momentum of the particles. The results of the spin transfer coefficient are in qualitative agreement with the DISTO experiment. The Lambda polarization data of 2.95 GeV/c are only conform with the DISTO experiment, while both the 2.70 GeV/c and 2.95 GeV/c data differ strongly from all previous measurements, whether exclusive or inclusive.
A feasibility study of ortho-positronium decays measurement with the J-PET scanner based on plastic scintillators
D. Kamińska, A. Gajos, E. Czerwiński, D. Alfs, T. Bednarski, P. Białas, C. Curceanu, K. Dulski, B. Głowacz, N. Gupta-Sharma, M. Gorgol, B. C. Hiesmayr, B. Jasińska, G. Korcyl, P. Kowalski, W. Krzemień, N. Krawczyk, E. Kubicz, M. Mohammed, Sz. Niedźwiecki, M. Pawlik-Niedźwiecka, L. Raczyński, Z. Rudy, M. Silarski, A. Wieczorek, W. Wiślicki, B. Zgardzińska, M. Zieliński, P. Moskal
abstract
We present a study of the application of the Jagiellonian Positron Emission Tomograph (J-PET) for the registration of gamma quanta from decays of ortho-positronium (o-Ps). The J-PET is the first positron emission tomography scanner based on organic scintillators in contrast to all current PET scanners based on inorganic crystals. Monte Carlo simulations show that the J-PET as an axially symmetric and high acceptance scanner can be used as a multi-purpose detector well suited to pursue research including e.g. tests of discrete symmetries in decays of ortho-positronium in addition
to the medical imaging. The gamma quanta originating from o-Ps decay interact in the plastic scintillators predominantly via the Compton effect, making the direct measurement of their energy impossible. Nevertheless, it is shown in this paper that the J-PET scanner will enable studies of the o-Ps->3g decays with angular and energy resolution equal to sigma(theta) = 0.4^{circ} and sigma(E) = 4.1 keV, respectively. An order of magnitude shorter decay time of signals from plastic scintillators with respect to the inorganic crystals results not only in better timing properties crucial for the reduction of physical and instrumental background, but also suppresses significantly the pileups, thus enabling compensation of the lower efficiency of the plastic scintillators by performing measurements with higher positron source activities.
Ranking and validation of the spallation models for description of intermediate mass fragment emission from p + Ag collisions at 480 MeV incident proton beam energy
S. Sharma, B. Kamys, F. Goldenbaum, D. Filges
abstract
Double-differential cross-sections d2?/d? dE for isotopically identified intermediate mass frag- ments (6Li up to 27Mg) from nuclear reactions induced by 480MeV protons impinging on a silver target were analyzed in the frame of a two-step model. The first step of the reaction was described by the intranu- clear cascade model INCL4.6 and the second one by four different models (ABLA07,GEM2, GEMINI++, and SMM). The experimental spectra reveal the presence of low-energy, isotropic as well as high-energy, forward-peaked contributions. The INCL4.6 model offers a possibility to describe the latter contribution for light intermediate mass fragments by coalescence of the emitted nucleons. The qualitative agreement of the model predictions with the data was observed but the high-energy tails of the spectra were signif- icantly overestimated. The shape of the isotropic part of the spectra was reproduced by all four models. The GEM2 model strongly underestimated the value of the cross-sections for heavier IMF whereas the SMM and ABLA07 models generally overestimated the data. The best quantitative description of the data was offered by GEMINI++, however, a discrepancy between the data and the model cross-sections still remained for almost all reaction products, especially at forward angles. It indicates that non-equilibrium processes are present which cannot be reproduced by the applied models. The goodness of the data de- scription was judged quantitatively using two statistical deviation factors, the H-factor and the M-factor, as a tool for ranking and validation of the theoretical models.
Search for an Isospin I =3 Dibaryon
P. Adlarson, ..., E. Czerwiński, O. Khreptak, W. Krzemień, P. Moskal, O. Rundel, I. Schätti-Ozerianska, M. Skurzok, M.J. Zieliński, et al.
abstract
Various theoretical calculations based on QCD or hadronic interactions predict that in addition to the recently observed dibaryon resonance d*(2380) with I(JP)=0(3+) there should also exist a dibaryon resonance with mirrored quantum numbers I(JP)=3(0+). We report here on a search for such a NN-decoupled state in data on the pp -> pp pi+ pi+ pi- pi- reaction.
Limit on the production of a new vector boson in e+e- -> Ug, U -> pi+pi- with the KLOE experiment
KLOE-2 Collaboration: A. Anastasi, E. Czerwiński, A. Gajos, D. Kamińska, W. Krzemień, P. Moskal, M. Silarski, W. Wiślicki et al.
abstract
The recent interest in a light gauge boson in the framework of an extra U(1) symmetry motivates searches in the mass range below 1 GeV. We present a search for such a particle, the dark photon, in e+e->Ug , U->pi+pi- based on 28 million e+e->pi+pi-g events collected at DAFNE by the KLOE experiment. The pi+pi- production by initial-state radiation compensates for a loss of sensitivity of previous KLOE U->e+e-, mu+mu- searches due to the small branching ratios in the rho-omega resonance region. We found no evidence for a signal and set a limit at 90% CL on the mixing strength between the photon and the dark photon, epsilon^2 , in the U mass range between 527 and 987MeV . Above 700 MeV this new limit is more stringent than previous ones.
Possibility of Measurement of Cross Section and Vector Analyzing Powers of p-3He Scattering at the Bronowice Cyclotron Center
I. Ciepał, A. Kozela , B. Głowacz , P. Kulessa , T. Pałasz, I. Skwira-Chalot , B. Włoch
abstract
A new possibility of continuation of few-nucleon dynamics studies at medium energies has appeared together with a new facility at the Institute of Nuclear Physics PAN in Kraków ? The Bronowice Cyclotron Center (CCB). The new cyclotron PROTEUS provides a proton beam in an energy range of 70?230 MeV. Current progress in the theoretical calculations for four-nucleon (4N) systems is a main motivation to investigate p ?3He scattering. Due to the fact that the beam cannot be polarized, the only possibility to study spin observables is to build a polarized 3He target system. A planned experiment assumes the construction of a cylindrical double Pyrex cell with separated pumping and target chambers with an additional polyamide film covering apertures for the passing beam and the reaction products. To polarize 3He gas, the spin-exchange optical pumping method will be used.
Determination of the 3gamma Fraction from Positron Annihilation in Mesoporous Materials for Symmetry Violation Experiment with J-PET Scanner
B. Jasińska, M. Gorgol, M. Wiertel, R. Zaleski, D. Alfs, T. Bednarski, P. Białas, E. Czerwiński, K. Dulski, A. Gajos B. Głowacz, D. Kamińska, Ł. Kapłon, G. Korcyl, P. Kowalski, T. Kozik, W. Krzemień, E. Kubicz, M. Mohammed, Sz. Niedźwiecki, M. Pałka, L. Raczyński, Z. Rudy, O. Rundel, N.G. Sharma, M. Silarski, A. Słomski, A. Strzelecki, A. Wieczorek, W. Wiślicki, B. Zgardzińska, M. Zieliński, P. Moskal
abstract
Various mesoporous materials were investigated to choose the best material for experiments requiring high yield of long-lived positronium. We found that the fraction of 3? annihilation determined using ?-ray energy spectra and positron annihilation lifetime spectra (PAL) changed from 20% to 25%. The 3? fraction and o-Ps formation probability in the polymer XAD-4 is found to be the largest. Elemental analysis performed using scanning electron microscope (SEM) equipped with energy-dispersive X-ray spectroscope EDS shows high purity of the investigated materials.
Sampling FEE and Trigger-less DAQ for the J-PET Scanner
G. Korcyl, D. Alfs, T. Bednarski, P. Białas, E. Czerwiński, K. Dulski, A. Gajos, B. Głowacz, B. Jasińska, D. Kamińska Ł. Kapłon, P. Kowalski, T. Kozik, W. Krzemień, E. Kubicz, M. Mohammed, Sz. Niedźwiecki, M. Pałka, M. Pawlik-Niedźwiecka, L. Raczyński, Z. Rudy, O. Rundel, N.G. Sharma, M. Silarski, A. Słomski, K. Stoła, A. Strzelecki, A. Wieczorek, W. Wiślicki, B.K. Zgardzińska, M. Zieliński, P. Moskal
abstract
In this paper, we present a complete Data Acquisition System (DAQ) together with the readout mechanisms for the J-PET tomography scanner. In general, detector readout chain is constructed out of Front-End Electronics (FEE) measurement devices such as Time-to-Digital or Analog-to-Digital Converters (TDCs or ADCs), data collectors and storage. We have developed a system capable for maintaining continuous readout of digitized data without preliminary selection. Such operation mode results in up to 8 Gbps data stream, therefore, it is required to introduce a dedicated module for on-line event building and feature extraction. The Central Controller Module, equipped with Xilinx Zynq SoC and 16 optical transceivers, serves as such true real time computing facility. Our solution for the continuous data recording (trigger-less) is a novel approach in such detector systems and assures that most of the information is preserved on the storage for further, high-level processing. Signal discrimination applies a unique method of using LVDS buffers located in the FPGA fabric.
Beam Profile Investigation of the New Collimator System for the J-PET Detector
E. Kubicz, M. Silarski, A. Wieczorek, D. Alfs, T. Bednarski, P. Białas, E. Czerwiński, A. Gajos, B. Głowacz, B. Jasińska D. Kamińska, G. Korcyl, P. Kowalski, T. Kozik, W. Krzemień, M. Mohammed, I. Moskal, S. Niedźwiecki, M. Pawlik-Niedźwiecka, L. Raczyński, Z. Rudy, A. Strzelecki, W. Wiślicki, M. Zieliński, B. Zgardzińska, P. Moskal
abstract
Jagiellonian Positron Emission Tomograph (J-PET) is a multi-purpose detector which will be used for search for discrete symmetries violations in the decays of positronium atoms and for investigations with positronium atoms in life-sciences and medical diagnostics. In this article, we present three methods for determination of the beam profile of collimated annihilation gamma quanta. Precise monitoring of this profile is essential for time and energy calibration of the J-PET detector and for the determination of the library of model signals used in the hit-time and hit-position reconstruction. We have shown that usage of two lead bricks with dimensions of 5 × 10 × 20 cm3 enables to form a beam of annihilation quanta with Gaussian profile characterized by 1 mm FWHM. Determination of this characteristic is essential for designing and construction the collimator system for the 24-module J-PET prototype. Simulations of the beam profile for different collimator dimensions were performed. This allowed us to choose optimal collimation system in terms of the beam profile parameters, dimensions and weight of the collimator taking into account the design of the 24-module J-PET detector.
Scatter Fraction of the J-PET Tomography Scanner
P. Kowalski, W. Wiślicki, L. Raczyński, D. Alfs, T. Bednarski, P. Białas, E. Czerwiński, A. Gajos, B. Głowacz, J. Jasińska D. Kamińska, G. Korcyl, T. Kozik, W. Krzemień, E. Kubicz, M. Mohammad, Sz. Niedźwiecki, M. Pałka, M. Pawlik-Niedźwiecka, Z. Rudy, M. Silarski, A. Wieczorek, B. Zgardzińska, M. Zieliński, P. Moskal
abstract
A novel Positron Emission Tomography system, based on plastic scintillators, is being developed by the J-PET Collaboration. In this article, we present the simulation results of the scatter fraction, representing one of the parameters crucial for background studies defined in the NEMA-NU-2-2012 norm. We elaborate an event selection methods allowing to suppress events in which gamma quanta were scattered in the phantom or underwent the multiple scattering in the detector. The estimated scatter fraction for the single-layer J-PET scanner varies from 37% to 53% depending on the applied energy threshold.
On Quasibound N*-Nuclei
N. G. Kelkar, D. Bedoya Fierro, P. Moskal
abstract
The possibility for the existence of unstable bound states of the S11 nucleon resonance N?(1535) and nuclei is investigated. These quasibound states are speculated to be closely related to the existence of the quasibound states of the eta mesons and nuclei. Within a simple model for the NN? interaction involving a pion and eta meson exchange, N??nucleus potentials for N??3He and N??24Mg are evaluated and found to be of a Woods?Saxon-like form which supports two to three bound states. In the case of N??3He, one state bound by only a few keV and another by 4 MeV is found. The results are however quite sensitive to the NN?? and NN?? vertex parameters. A rough estimate of the width of these states, based on the mean free path of the exchanged mesons in the nuclei, leads to very broad states with ? ? 80 and 110 MeV for N??3He and N??24Mg respectively.
eta' Interactions with Nucleons and Nuclei
S. D. Bass, P. Moskal
abstract
We summarise recent progress in theory and experiment towards understanding of ??-meson interactions with nucleons and nuclei. Highlights include the production mechanism of ?? mesons in proton?proton collisions close to the threshold, the ?? effective mass shift in nuclei and the determination of the ??-nucleon scattering length in free space.
Design of the SABAT System for Underwater Detection of Dangerous Substances
M. Silarski, D. Hunik, M. Smolis, S. Tadeja, P. Moskal
abstract
We present status of simulations used to design a novel device for the detection of hazardous substances in the aquatic environment using neutron activation. Unlike the other considered methods based on this technique, we propose to use guides for neutron and gamma quanta which speeds up and simplifies identification. First preliminary results show that both the neutron guide and the ?-ray guide increase the performance of underwater threats detection.
Application of the compress sensing theory for improvement of the TOF resolution in a novel J-PET instrument
L. Raczyński, P. Moskal, P. Kowalski, W. Wiślicki, T. Bednarski, P. Białas, E. Czerwiński, A. Gajos, Ł. Kapłon, A. Kochanowski, G. Korcyl, J. Kowal, T. Kozik, W. Krzemień, E. Kubicz, Sz. Niedźwiecki, M. Pałka, Z. Rudy, P. Salabura, N. Gupta-Sharma, M. Silarski, A. Słomski, J. Smyrski, A. Strzelecki, A. Wieczorek, M. Zieliński, N. Zoń
abstract
Trilateration-based reconstruction of ortho-positronium decays into three photons with the J-PET detector
A. Gajos, D. Kamińska, E. Czerwiński, D. Alfs, T. Bednarski, P. Białas, B. Głowacz, M. Gorgol, B. Jasińska, Ł. Kapłon, G. Korcyl, P. Kowalski, T. Kozik, W. Krzemień, E. Kubicz, M. Mohammed, Sz. Niedźwiecki, M. Pałka, M. Pawlik-Niedźwiecka, L. Raczyński, Z. Rudy, O. Rundel, N.G. Sharma, M. Silarski, A. Słomski, A. Strzelecki, A. Wieczorek, W. Wiślicki, B. Zgardzińska, M. Zieliński, P. Moskal
abstract
This work reports on a new reconstruction algorithm allowing us to reconstruct the decays of ortho-positronium atoms into three photons using the places and times of photons recorded in the detector. The method is based on trilateration and allows for a simultaneous reconstruction of both location and time of the decay. Results of resolution tests of the new reconstruction in the J-PET detector based on Monte Carlo simulations are presented, which yield a spatial resolution at the level of 2 cm (FWHM) for X and Y and at the level of 1 cm (FWHM) for Z available with the present resolution of J-PET after application of a kinematic fit. Prospects of employment of this method for studying angular correlations of photons in decays of polarized ortho-positronia for the needs of tests of CP and CPT discrete symmetries are also discussed. The new reconstruction method allows for discrimination of background from random three-photon coincidences as well as for application of a novel method for determination of the linear polarization of ortho-positronium atoms, which is also introduced in this work.
Electron-cooled accumulation of 4 × 10^9 positrons for production and storage of antihydrogen atoms
D. W. Fitzakerley, M. C. George, E. A. Hessels, T. D. G. Skinner, C. H. Storry, M. Weel, G. Gabrielse, C. D. Hamley, N. Jones, K. Marable, E. Tardiff, D. Grzonka, W. Oelert and M. Zieliński (ATRAP Collaboration)
abstract
Four billion positrons (e+) are accumulated in a Penning?Ioffe trap apparatus at 1.2 K and <6 × 10?17 Torr. This is the largest number of positrons ever held in a Penning trap. The e+ are cooled by collisions with trapped electrons (e?) in this first demonstration of using e? for efficient loading of e+ into a Penning trap. The combined low temperature and vacuum pressure provide an environment suitable for antihydrogen production, and long antimatter storage times, sufficient for high-precision tests of antimatter gravity and of CPT.
Large numbers of cold positronium atoms created in laser-selected Rydberg states using resonant charge exchange
R. McConnell, G. Gabrielse, W. S. Kolthammer, P. Richerme, A. Müllers, J. Walz, D. Grzonka, M. Zieliński, D. Fitzakerley, M. C. George, E. A. Hessels, C. H. Storry and M. Weel (ATRAP Collaboration)
abstract
Lasers are used to control the production of highly excited positronium atoms (Ps*). The laser light excites Cs atoms to Rydberg states that have a large cross section for resonant charge-exchange collisions with cold trapped positrons. For each trial with 30 million trapped positrons, more than 700 000 of the created Ps* have trajectories near the axis of the apparatus, and are detected using Stark ionization. This number of Ps* is 500 times higher than realized in an earlier proof-of-principle demonstration (2004 Phys. Lett. B 597 257). A second charge exchange of these near-axis Ps* with trapped antiprotons could be used to produce cold antihydrogen, and this antihydrogen production is expected to be increased by a similar factor.
Time resolution of the plastic scintillator strips with matrix photomultiplier readout for J-PET tomograph
P. Moskal, O. Rundel, D. Alfs, T. Bednarski, P. Białas, E. Czerwiński, A. Gajos, K. Giergiel, M. Gorgol, B. Jasińska, D. Kamińska, Ł. Kapłon, G. Korcyl, P. Kowalski, T. Kozik, W. Krzemień, E. Kubicz, Sz. Niedźwiecki, M. Pałka, L. Raczyński, Z. Rudy, N.G. Sharma, A. Słomski, M. Silarski, A. Strzelecki, A. Wieczorek, W. Wiślicki, P. Witkowski, M. Zieliński, N. Zoń
abstract
Recent tests of a single module of the Jagiellonian Positron Emission
Tomography system (J-PET) consisting of 30 cm long plastic scintillator
strips have proven its applicability for the detection of annihilation quanta
(0.511 MeV) with a coincidence resolving time (CRT) of 0.266 ns. The
achieved resolution is almost by a factor of two better with respect to the
current TOF-PET detectors and it can still be improved since, as it is shown
in this article, the intrinsic limit of time resolution for the determination of
time of the interaction of 0.511 MeV gamma quanta in plastic scintillators
is much lower. As the major point of the article, a method allowing to
record timestamps of several photons, at two ends of the scintillator strip,
by means of matrix of silicon photomultipliers (SiPM) is introduced. As a
result of simulations, conducted with the number of SiPM varying from 4 to 42, it is shown that the improvement of timing resolution saturates with
the growing number of photomultipliers, and that the 2×5 configuration at
two ends allowing to read twenty timestamps, constitutes an optimal solution.
The conducted simulations accounted for the emission time distribution,
photon transport and absorption inside the scintillator, as well as quantum
efficiency and transit time spread of photosensors, and were checked based on
the experimental results. Application of the 2×5 matrix of SiPM allows for
achieving the coincidence resolving time in positron emission tomography of
0.170 ns for 15 cm axial field-of-view (AFOV) and 0.365 ns for 100 cm
AFOV. The results open perspectives for construction of a cost-effective TOFPET
scanner with significantly better TOF resolution and larger AFOV with
respect to the current TOF-PET modalities.
Overview of the software architecture and data flow for the J-PET tomography device
W. Krzemień, D. Alfs, P. Białas, E. Czerwiński, A. Gajos, B. Głowacz, B. Jasińska, D. Kamińska, G. Korcyl, P. Kowalski, T. Kozik, E. Kubicz, Sz. Niedźwiecki, M. Pawlik-Niedźwiecka, L. Raczyński, Z. Rudy, M. Silarski, A. Strzelecki, A. Wieczorek, W. Wiślicki, M. Zieliński, P. Moskal
abstract
Modern TOF-PET scanner systems require high-speed computing resources for efficient data processing, monitoring and image reconstruction. In this article we present the data flow and software architecture for the novel TOF-PET scanner developed by the J-PET collaboration. We discuss the data acquisition system, reconstruction framework and some image reconstruction issues. Also, the concept of computing outside hospitals in the remote centers such as 'Swierk Computing Centre in Poland is presented
Potential of the J-PET Detector for Studies of Discrete Symmetries in Decays of Positronium Atom - a Purely Leptonic System
P. Moskal, D. Alfs, T. Bednarski, P. Białas, E. Czerwinski, C. Curceanu, A. Gajos, B. Głowacz, M. Gorgol, B.C. Hiesmayr, B. Jasinska, D. Kaminska, G. Korcyl, P. Kowalski, T. Kozik, W. Krzemien , N. Krawczyk, E. Kubicz, M. Mohammed, Sz. Niedzwiecki, M. Pawlik-Niedzwiecka, L. Raczynski, Z. Rudy, M. Silarski, A. Wieczorek, W. Wislicki, M. Zielinski
abstract
The Jagiellonian Positron Emission Tomograph (J-PET) was constructed
as a prototype of the cost-effective scanner for the simultaneous
metabolic imaging of the whole human body. Being optimized for the detection
of photons from the electron?positron annihilation with high timeand
high angular-resolution, it constitutes a multi-purpose detector providing
new opportunities for studying the decays of positronium atoms.
Positronium is the lightest purely leptonic object decaying into photons.
As an atom bound by a central potential, it is a parity eigenstate, and
as an atom built out of an electron and an anti-electron, it is an eigenstate
of the charge conjugation operator. Therefore, the positronium is
a unique laboratory to study discrete symmetries whose precision is limited,
in principle, by the effects due to the weak interactions expected at the level of (10????14) and photon?photon interactions expected at the
level of (10????9). The J-PET detector enables to perform tests of discrete
symmetries in the leptonic sector via the determination of the expectation
values of the discrete-symmetries-odd operators, which may be constructed
from the spin of ortho-positronium atom and the momenta and polarization
vectors of photons originating from its annihilation. In this article, we
present the potential of the J-PET detector to test the C, CP, T and CPT
symmetries in the decays of positronium atoms.
Upper limits for the production of the eta-mesic Helium in the dd ->3Henpi0 and dd -> 3Heppi- reactions
M. Skurzok, W. Krzemień, O. Rundel, P. Moskal
abstract
We performed a search for 4 He-eta bound state in dd->3He n pi0 and dd->3He p pi- reactions with the WASA-at-COSY facility using a ramped beam technique. The measurement was carried out with high statistics and high acceptance. The signature of eta-mesic nuclei was searched for by the measurement of the excitation functions in the vicinity of the eta production threshold for each of the considered channels. We did not observe the narrow structure which could be interpreted as a bound state. The preliminary upper limits of the total cross sections for the bound state production and decay varies from 21 nb to 36 nb for the dd->3He n pi0 channel, and from 5 nb to 9 nb for the dd->3He p pi- channel for the bound state width ranging from 5 to 50 MeV.
Precision measurement of the eta to pi+pi-pi0 Dalitz plot distribution with the KLOE detector
KLOE-2 Collaboration: A. Anastasi, E. Czerwiński, A. Gajos, D. Kamińska, W. Krzemień, P. Moskal, M. Silarski, W. Wiślicki, et al.
abstract
Using 1.6 fb^-1 of e+e-to phi eta gamma data collected with the KLOE detector at DAFNE, the Dalitz plot distribution for the eta to pi+ pi- pi0 decay is studied with the world's largest sample of ~4.7 10^6 events. The Dalitz plot density is parametrized as a polynomial expansion up to cubic terms in the normalized dimensionless variables X and Y. The experiment is sensitive to all charge conjugation conserving terms of the expansion, including a gX2Y term. The statistical uncertainty of all parameters is improved by a factor two with respect to earlier measurements.
Measurement of the phi->pi0e+e- transition form factor with the KLOE detector
KLOE-2 Collaboration: A. Anastasi, E. Czerwiński, A. Gajos, D. Kamińska, W. Krzemień, P. Moskal, M. Silarski, W. Wiślicki, et al.
abstract
A measurement of the vector to pseudoscalar conversion decay phi->pi0e+e- with the KLOE experiment is presented. A sample of ~9500 signal events was selected from a data set of 1.7 fb^(-1) of e+e- collisions at sqrt(s)~m(phi) collected at the DAFNE e+e- collider. These events were used to obtain the first measurement of the transition form factor |F_{phi,pi^0}(q2)| and a new measurement of the branching ratio of the decay: BR(phi->pi0e+e-)=(1.35+/-0.05+0.05?0.10)×10^(-5). The result improves significantly on previous measurements and is in agreement with theoretical predictions.
Measurement of the vec{n} p->d pi0 pi0 Reaction with Polarized Beam in the Region of the d*(2380) Resonance
P. Adlarson, ..., E. Czerwiński, M. Hodana, J. Klaja, W. Krzemień, P. Moskal, I. Ozerianska, O. Rundel, M. Skurzok, M. Zieliński et al.
abstract
We report on a high-statistics measurement of the most basic double pionic fusion reaction vec{n}p -> dpi0pi0 over the energy region of the d*(2380) resonance by use of a polarized deuteron beam and observing the double fusion reaction in the quasifree scattering mode. The measurements were performed with the WASA detector setup at COSY. The data reveal substantial analyzing powers and confirm conclusions about the d? resonance obtained from unpolarized measurements. We also confirm the previous unpolarized data obtained under complementary kinematic conditions.
High precision measurement of the associated strangeness production in proton proton interactions
S. Jowzaee, ..., P. Moskal, ... , J. Smyrski
abstract
A new high precision measurement of the reaction pp N pK ` Lambda at a beam momentum of 2.95 GeV/c with more than 200 000 analyzed events allows a detailed analysis of differential observables and their inter-dependencies. Correlations of the angular distributions with momenta are examined. The invariant mass distributions are compared for different regions in the Dalitz plots. The cusp structure at the NSigma threshold is described with the Flatte formalism and its variation in the Dalitz plot is analyzed.
Searches for discrete symmetries violation in ortho-positronium decay using the J-PET detector
D. Kamińska, A. Gajos, E. Czerwiński, T. Bednarski, P. Białas, M. Gorgol, B. Jasińska, Ł. Kapłon, G. Korcyl, P. Kowalski, T. Kozik, W. Krzemień, E. Kubicz, S. Niedźwiecki, M. Pałka, L. Raczyński, Z. Rudy, O. Rundel, N. Gupta-Sharma, M. Silarski, A. Słomski, A. Strzelecki, A. Wieczorek, W. Wiślicki, M. Zieliński, B. Zgardzińska, P. Moskal
abstract
In this paper, we present prospects for using the Jagiellonian positron emission tomograph (J-PET)
detector to search for discrete symmetries violations in a purely leptonic system of the positronium atom. We
discuss tests of CP and CPT symmetries by means of ortho-positronium decays into three photons. No zero
expectation values for chosen correlations between ortho-positronium spin and momentum vectors of photons
would imply the existence of physics phenomena beyond the standard model. Previous measurements resulted
in violation amplitude parameters for CP and CPT symmetries consistent with zero, with an uncertainty of
about 10?3. The J-PET detector allows to determine those values with better precision, thanks to the unique
time and angular resolution combined with a high geometrical acceptance. Achieving the aforementioned is possible
because of the application of polymer scintillators instead of crystals as detectors of annihilation quanta.
Studies of unicellular microorganisms Saccharomyces cerevisiae by means of positron annihilation lifetime spectroscopy
E. Kubicz, B. Jasińska, B. Zgardzińska, T. Bednarski, P. Białas, E. Czerwiński, A. Gajos, M. Gorgol, D. Kamińska, Ł. Kapłon, A. Kochanowski, G. Korcyl, P. Kowalski, T. Kozik, W. Krzemień, S. Niedźwiecki, M. Pałka, L. Raczyński, Z. Rajfur, Z. Rudy, O. Rundel, N. Gupta-Sharma, M. Silarski, A. Słomski, A. Strzelecki, A. Wieczorek, W. Wiślicki, M. Zieliński, P. Moskal
abstract
Results of positron annihilation lifetime spectroscopy (PALS) and microscopic studies on simple microorganisms,
brewing yeasts, are presented. Lifetime of ortho-positronium (o-Ps) were found to change from 2.4 to 2.9 ns
(longer-lived component) for lyophilized and aqueous yeasts, respectively. Also hygroscopicity of yeasts in time was
examined, allowing to check how water ? the main component of the cell ? affects PALS parameters, thus lifetime
of o-Ps were found to change from 1.2 to 1.4 ns (shorter-lived component) for the dried yeasts. The time suffi cient
to hydrate the cells was found below 10 hours. In the presence of liquid water, an indication of reorganization of
yeast in the molecular scale was observed. Microscopic images of the lyophilized, dried, and wet yeasts with best
possible resolution were obtained using inverted microscopy (IM) and environmental scanning electron microscopy
(ESEM) methods. As a result, visible changes to the surface of the cell me mbrane were observed in ESEM images.
K- absorption on two nucleons and ppK- bound state search in the E0p final state
O. Vazquez Doce, L. Fabbietti, M. Cargnelli, C. Curceanu, J. Marton, K. Piscicchia, A. Scordo, D. Sirghi, I. Tucakovic, S. Wycech, J. Zmeskal, A. Anastasi, F. Curciarello, E. Czerwinski, W. Krzemien, G. Mandaglio, M. Martini, P. Moskal, V. Patera, E. Perez del Rio, M. Silarski
abstract
We report the measurement of K- absorption processes in the Sigma_0p final state and the first exclusive measurement of the two nucleon absorption (2NA) with the KLOE detector. The 2NA process without further interactions is found to be 12% of the sum of all other contributing processes, including absorption on three and more nucleons or 2NA followed by final state interactions with the residual nucleons. We also determine the possible contribution of the ppK- bound state to the ?0p final state. A yield of ppK-/K_stop is found to be (0.044+/-0.009stat+0.004+/-0.005syst)?10?2 but its statistical significance based on an F-test is only 1sigma.
Limit on the production of a low-mass vector boson in e+e- ->U, U->e+e- with the KLOE experiment
A. Anastasi, E. Czerwiński, A. Gajos, D. Kamińska, W. Krzemień, P. Moskal, M. Silarski, W. Wiślicki, et al.
abstract
The existence of a new force beyond the Standard Model is compelling because it could explain several striking astrophysical observations which fail standard interpretations. We searched for the light vector mediator of this dark force, the U boson, with the KLOE detector at the DAFNE e+e? collider. Using an integrated luminosity of 1.54 fb^-1, we studied the process e+e->U, with U->e+e-, using radiative-return to search for a resonant peak in the dielectron invariant-mass distribution. We did not find evidence for a signal, and set a 90\%~CL upper limit on the mixing strength between the Standard Model photon and the dark photon, ?^2, at 10^-6--10^-4 in the 5--520~MeV/c2 mass range.
Reconstruction of hit time and hit position of annihilation quanta in the J-PET detector usi ng the Mahalanobis distance
N. G. Sharma, M. Silarski, T. Bednarski, P. Białas, E. Czerwiński, A. Gajos, M. Gorgol, B. Jasińska, D. Kamińska, Ł. Kapłon, G. Korcyl, P. Kowalski, T. Kozik, W. Krzemień, E. Kubicz, Sz. Niedźwiecki, M. Pałka, L. Raczyński, Z. Rudy, O. Rundel, A. Słomski, A. Strzelecki, A. Wieczorek, W. Wiślicki, M. Zieliński, B. Zgardzińska, P. Moskal
abstract
The J-PET detector being developed at Jagiellonian University, is a Positron Emission Tomograph composed of the long strips of polymer scintillators. At the same time it is a detector system which will be used for studies of the decays of positronium atoms. The shape of photomultiplier signals depends on the hit-time and hit-position of the gamma quantum. In order to take advantage of this fact a dedicated sampling front-end electronics which enables to sample signals in voltage domain with the time precision of about 20 ps and novel reconstruction method based on the comparison of examined signal with the model signals stored in the library has been developed. As a measure of the similarity we use the Mahalanobis distance. The achievable position and time-resolution depends on number and values of the threshold levels at which the signal is sampled. A reconstruction method, as well as preliminary results are presented and discussed.
PALS investigations of free volumes thermal expansion of J-PET plastic scintillator synthesized in polystyrene matrix
A. Wieczorek, B. Zgardzińska, B. Jasińska, M. Gorgol, T. Bednarski, P. Białas, E. Czerwiński, A. Gajos, D. Kamińska, Ł. Kapłon, A. Kochanowski, G. Korcyl, P. Kowalski, T. Kozik, W. Krzemień, E. Kubicz, Sz. Niedźwiecki, M. Pałka, L. Raczyński, Z. Rudy, O. Rundel, N.G. Sharma, M. Silarski, A. Słomski, A. Strzelecki, W. Wiślicki, M. Zieliński, P. Moskal
abstract
The polystyrene dopped with 2,5-diphenyloxazole as a primary fluor and 2-(4-styrylphenyl)benzoxazole as a wavelength shifter, prepared as a plastic scintillator was investigated using positronium probe in wide range of temperatures from 123 to 423 K. Three structural transitions at 260 K, 283 K and 370 K were found in the material. In the o-Ps intensity dependence on temperature, the significant hysteresis is observed. Heated to 370 K, the material exhibits the o-Ps intensity variations in time.
Processing optimization with parallel computing for the J-PET scanner
W. Krzemień, M. Bała, T. Bednarski, P. Białas, E. Czerwiński, A. Gajos, M. Gorgol, B. Jasińska, D. Kamińska, Ł. Kapłon, G. Korcyl, P. Kowalski, T. Kozik, E. Kubicz, Sz. Niedźwiecki, M. Pałka, L. Raczyński, Z. Rudy, O. Rundel, N.G. Sharma, M. Silarski, A. Słomski, K. Stola, A. Strzelecki, D. Trybek, Anna Wieczorek, W. Wiślicki, M. Zieliński, B. K. Zgardzińska, P. Moskal
abstract
The Jagiellonian-PET (J-PET) collaboration is developing a prototype TOF-PET detector based on long polymer scintillators. This novel approach exploits the excellent time properties of the plastic scintillators, which permit very precise time measurements. The very fast, FPGA-based front-end electronics and the data acquisition system, as well as, low- and high-level reconstruction algorithms were specially developed to be used with the J-PET scanner. The TOF-PET data processing and reconstruction are time and resource demanding operations, especially in case of a large acceptance detector, which works in triggerless data acquisition mode. In this article, we discuss the parallel computing methods applied to optimize the data processing for the J-PET detector. We begin with general concepts of parallel computing and then we discuss several applications of those techniques in the J-PET data processing.
Investigation of the low energy kaons hadronic interactions in light nuclei by AMADEUS
K. Piscicchia, ... ,P.Moskal, ...,M. Silarski, M. Skurzok, ..., et al.
abstract
The AMADEUS experiment aims to provide unique quality data for K- interaction with nucleons and light nuclei, both at-rest and in-flight (for K- momenta of about 100 MeV). The goal is to solve longstanding open issues in the non-perturbative QCD in the strangeness sector, like the nature of the Lambda(1405) state, the resonant versus non-resonant yield in nuclear K- capture and the properties of kaonic nuclear clusters which are strongly related to the multi-nucleon absorption processes. We can take advantage of the DAFNE collider representing a unique source of monochromatic low-momentum kaons, whose nuclear interaction with the materials of the KLOE detector (used as an active target) furnish us excellent acceptance and resolution data for K- capture on H,4He,9Be and12C, both at-rest and in-flight. AMADEUS step 0 consisted in the analysis of the 2004-2005 KLOE data. A second step consisted in the implementation in the central region of the KLOE detector of a pure graphite target, providing a high statistic sample of K^{?}^{12} C nuclear captures at rest. For the future, new setups for various dedicated targets are under preparation.
Project of the underwater system for chemical threat detection
M. Silarski, D. Hunik, P. Moskal, M. Smolis, S. Tadeja
abstract
In this article we describe a novel method for the detection of explosives and other hazardous substances in the marine environment using neutron activation. Unlike the other considered methods based on this technique we propose to use guides forneutron and gamma quanta which speeds up and simplifies identification. Moreover, it may provide a determination of the density distribution of a dangerous substance. First preliminary results of Monte Carlo simulations dedicated for design of a device exploiting this method are also presented.
Angular Asymmetry in the Pro duction of Light and Heavy Recoil Nuclides in Proton Induced Reaction with Au Target at GeV Energies
S. Sharma, B. Kamys
abstract
It is shown that model calculations are able to reproduce main properties in terms of experimental mass
dependence of the forward-backward asymmetry of the emitted reaction products from proton-Au collisions in the
proton beam energy range from 1 GeV to 3 GeV. Qualitative as well as quantitative comparisons are done between
the measurements and the calculations performed by means of the intra nuclear cascade code INCL4.6 coupled
with four different codes: SMM, GEMINI++, ABLA07, and GEM2 with the aim to validate the selected reaction
models.
Multiple Scattering and Accidental Coincidences in the J-PET Detector Simulated Using GATE Package
P. Kowalski, P. Moskal, W. Wislicki, L. Raczynski, T. Bednarski, P. Bialas, J. Bulka, E. Czerwinski, A. Gajos, A. Gruntowski, D. Kaminska, L. Kaplon, A. Kochanowski, G. Korcyl, J. Kowal, T. Kozik, W. Krzemien, E. Kubicz, S. Niedzwiecki, M. Palka, Z. Rudy, P. Salabura, NG. Sharma, M. Silarski, A. Slomski, J. Smyrski, A. Strzelecki, A. Wieczorek, I. Wochlik, M. Zielinski, N. Zon
abstract
Novel positron emission tomography system, based on plastic scintillators, is developed by the J-PET collaboration. In order to optimize geometrical configuration of built device, advanced computer simulations are performed. Detailed study is presented of background given by accidental coincidences and multiple scattering of gamma quanta.
A pilot study of the novel J-PET plastic scintillator with 2-(4-styrylphenyl)benzoxazole as a wavelength shifter
A. Wieczorek, P. Moskal, Sz. Niedźwiecki, T. Bednarski, P. Białas, E. Czerwiński, A. Danel, A. Gajos, A. Gruntowski, D. Kamińska, Ł. Kapłon, A. Kochanowski, G. Korcyl, J. Kowal, P. Kowalski, T. Kozik, W. Krzemień, E. Kubicz, M. Molenda, M. Pałka, L. Raczyński, Z. Rudy, O. Rundel, P. Salabura, N.G. Sharma, M. Silarski, A. Słomski, J. Smyrski, A. Strzelecki, T. Uchacz, W. Wiślicki, M. Zieliński, N. Zoń
abstract
For the first time a molecule of 2-(4-styrylphenyl)benzoxazole containing benzoxazole and stilbene groups is applied as a scintillator dopant acting as a wavelength shifter. In this article a light yield of the plastic scintillator, prepared from styrene doped with 2 wt% of 2,5-diphenylbenzoxazole and 0.03 wt% of 2-(4-styrylphenyl)benzoxazole, is determined to be as large as 60% ? 2% of the anthracene light output. There is a potential to improve this value in the future by the optimization of the additives concentrations.
Compressive sensing of signals generated in plastic scintillators in a novel J-PET instrument
L. Raczyński, P. Moskal, P. Kowalski, W. Wiślicki, T. Bednarski, P. Białas, E. Czerwiński, A. Gajos, Ł. Kapłon, A. Kochanowski, G. Korcyl, J. Kowal, T. Kozik, W. Krzemień, E. Kubicz, Sz. Niedźwiecki, M. Pałka, Z. Rudy, O. Rundel, P. Salabura, N.G. Sharma, M. Silarski, A. Słomski, J. Smyrski, A. Strzelecki, A. Wieczorek, M. Zieliński, N. Zoń
abstract
The J-PET scanner, which allows for single bed imaging of the whole human body, is currently under development at the Jagiellonian University. The discussed detector offers improvement of the Time of Flight (TOF) resolution due to the use of fast plastic scintillators and dedicated electronics allowing for sampling in the voltage domain of signals with durations of few nanoseconds. In this paper we show that recovery of the whole signal, based on only a few samples, is possible. In order to do that, we incorporate the training signals into the Tikhonov regularization framework and we perform the Principal Component Analysis decomposition, which is well known for its compaction properties. The method yields a simple closed form analytical solution that does not require iterative processing. Moreover, from the Bayes theory the properties of regularized solution, especially its covariance matrix, may be easily derived. This is the key to introduce and prove the formula for calculations of the signal recovery error. In this paper we show that an average recovery error is approximately inversely proportional to the number of acquired samples.
Search for eta-mesic Nuclei with WASA-at-COSY
W. Krzemień, P. Moskal, M. Skurzok
abstract
We search for an evidence of ?-mesic He with the WASA detector. Two dedicated experiments were performed at the Cooler Synchrotron COSY-Jülich. The experimental method is based on the measurement of the excitation functions for the two reaction channels: dd ?3He p?? and dd ?3He n?0, where the outgoing N?? pairs originate from the conversion of the ? meson on a nucleon inside the He nucleus. In this contribution, the experimental method is shortly described and the current status of the analysis is presented.
Analysis framework for the J-PET scanner
W. Krzemień, A. Gajos, A. Gruntowski, K. Stola, D. Trybek, T. Bednarski, P. Białas, E. Czerwiński, D. Kamińska, L. Kapłon, A. Kochanowski, G. Korcyl, J. Kowal, P. Kowalski, T. Kozik, E. Kubicz, P. Moskal, Sz. Niedźwiecki, M. Pałka, L. Raczyński, Z. Rudy, P. Salabura, N. G. Sharma, M. Silarski, A. Słomski, J. Smyrski, A. Strzelecki, A. Wieczorek, W. Wiślicki, M. Zieliński, N. Zoń
abstract
J-PET analysis framework is a flexible, lightweight, ROOT-based software package which provides the tools to develop reconstruction and calibration procedures for PET tomography. In this article we present the implementation of the full data-processing chain in the J-PET framework which is used for the data analysis of the J-PET tomography scanner. The Framework incorporates automated handling of PET setup parameters' database as well as high level tools for building data reconstruction procedures. Each of these components is briefly discussed.
Hit time and hit position reconstruction in the J-PET detector based on a library of averaged model signals
P. Moskal, N.G.Sharma, M.Silarski, T. Bednarski, P. Białas, J. Bułka, E. Czerwiński, A. Gajos, D. Kamińska, L. Kapłon, A. Kochanowski, G. Korcyl, J. Kowal, P. Kowalski, T. Kozik, W. Krzemień, E. Kubicz, Sz. Niedźwiecki, M. Pałka, L. Raczyński, Z. Rudy, O. Rundel, P. Salabura, A. Słomski, J. Smyrski, A. Strzelecki, A. Wieczorek, W. Wiślicki, I. Wochlik, M. Zieliński, N. Zoń
abstract
n this article we present a novel method of hit time and hit position reconstruction in long scintillator detectors. We take advantage of the fact that for this kind of detectors amplitude and shape of registered signals depends strongly on the position where particle hit the detector. The reconstruction is based on determination of the degree of similarity between measured and averaged signals stored in a library for a set of well-defined positions along the scintillator. Preliminary results of validation of the introduced method with experimental data obtained by means of the double strip prototype of the J-PET detector are presented.
GPU accelerated image reconstruction in a two-strip J-PET tomograph
P. Białas, J. Kowal, A. Strzelecki, T. Bednarski, E. Czerwiński, A. Gajos, D. Kamińska, Ł. Kapłon, A. Kochanowski, G. Korcyl, P. Kowalski, T. Kozik, W. Krzemień, E. Kubicz, P. Moskal, Sz. Niedźwiecki, M. Pałka, L. Raczyński, Z. Rudy, O. Rundel, P. Salabura, N.G. Sharma, M. Silarski, A. Słomski, J. Smyrski, A. Wieczorek, W. Wiślicki, M. Zieliński, N. Zoń
abstract
We present a fast GPU implementation of the image reconstruction routine, for a novel two strip PET detector that relies solely on the time of flight measurements.
Luminosity determination for the deutron-deutron reactions using free and quasi-free reactions with WASA-at-COSY detector
M. Skurzok, P. Moskal, W. Krzemień
abstract
Two methods of the luminosity determination for the experiment performed by WASA col- laboration to search for 4He-eta bound state are presented. During the measurement the tech- nique of continous change of the beam momentum in one accelerator cycle (called ramped beam) was applied. This imposes the requirement to determine not only the total integrated luminosity, but also its variation as a function of the beam momentum.
Study of the KS KL -> 3pi0, pi l nu process for Time reversal symmetry test at KLOE-2
A. Gajos on behalf of the KLOE-2 Collaboration
abstract
This work presents prospects for conducting a novel direct test of time-reversal symmetry at the KLOE-2 experiment. Quantum entanglement of neutral K meson pairs uniquely available at KLOE-2 allows to probe directly the time-reversal symmetry (T ) independently of CP violation. This is achieved by a comparison of probabilities for a transition between flavour and CP-definite states and its inverse obtained through exchange of initial and final states. As such, a test requires the reconstruction of the KL ? 3?0 decay accompanied by KS ? ????? with good timing information, a new reconstruction method for this process is also presented which is capable of reconstructing the KL ? 3?0 decay with decay time resolution of O(1?S).
Determination of the COSY Proton Beam Polarization Using the WASA Detector
I. Schätti-Ozerianska, P. Moskal, M. Zieliński
abstract
The dynamics of ?-meson production and the interaction of ? mesons with nucleons can be studied using the pp ? pp? reaction via measurements of the analyzing power Ay. To this end, we have performed a measurement of the pp ? pp? reaction using the WASA-at-COSY detector, which provides large acceptance and is ?-symmetric. The experiment was carried out for the beam momenta of 2026 MeV/c and 2188 MeV/c. In this article, we present a method and results for the determination of the degree of the beam polarization.
Improved KS Tagging Procedure and Its Impact on Physics at KLOE-2
M. Silarski
abstract
The KLOE experiment at the DA?NE ?-factory performed precise studies of charged and neutral kaon physics, low energy QCD, as well as tests of CP and CPT invariance. For the new run, the KLOE has been upgraded by adding new tagger systems for the ?? physics, the inner tracking chamber and two calorimeters in the final focusing region. We are also improving on kaon identification techniques, in particular algorithms for the KS meson tagging. In this article, we discuss the impact of the improved tagging procedure on studies of the KS decays.
Measurement of the Strong Interaction Induced Shift and Width of the 1s State of Kaonic Deuterium at J-PARC
J. Zmeskal, C. Curceanu, M. Sato, R.S. Hayano, P. Moskal, M. Silarski, et al.
abstract
The antikaon?nucleon (KN) interaction close to threshold provides crucial information on the interplay between spontaneous and explicit chiral symmetry breaking in low-energy QCD. In this context, the importance of kaonic deuterium X-ray spectroscopy has been well recognized, but no experimental results have yet been obtained due to the difficulty of the measurement. We propose to measure the shift and width of the kaonic deuterium 1s state with an accuracy of 60 eV and 140 eV, respectively, at J-PARC. These results, together with the kaonic hydrogen data (KpX at KEK, DEAR and SIDDHARTA at DA?NE), will then permit the determination of values of both the isospin I = 0 and I = 1 antikaon?nucleon scattering lengths and will provide the most stringent constraints on the antikaon?nucleon interaction, promising a breakthrough. Refined Monte Carlo studies were performed, including the investigation of background suppression factors for the described setup. These studies have demonstrated the feasibility of determining the shift and width of the kaonic deuterium atom 1s state with the desired accuracy of 60 eV and 140 eV.
Unprecedented Studies of the Low-energy Negatively Charged Kaons Interactions in Nuclear Matter by AMADEUS
C. Curceanu, K. Piscicchia, M. Bazzi, C. Berucci, D. Bosnar, A.M. Bragadireanu, A. Clozza, M. Cargnelli, A. D'Uffizi, L. Fabbietti, C. Fiorini, F. Ghio, C. Guaraldo, M. Iliescu, P. Levi Sandri, J. Marton, D. Pietreanu, M. Poli Lener, R. Quaglia, A. Romero Vidal, E. Sbardella, A. Scordo, H. Shi, D. Sirghi, F. Sirghi, M. Skurzok, I. Tucakovic, O. Vazquez Doce, E. Widmann, J. Zmeskal
abstract
The AMADEUS experiment aims to provide unique quality data of K? hadronic interactions in light nuclear targets, in order to solve fundamental open questions in the non-perturbative strangeness QCD sector, like the controversial nature of the ?(1405) state, the yield of hyperon formation below threshold, the yield and shape of multi-nucleon K? absorption, processes which are intimately connected to the possible existence of exotic antikaon multi-nucleon clusters. AMADEUS takes advantage of the DA?NE collider, which provides a unique source of monochromatic low-momentum kaons and exploits the KLOE detector as an active target, in order to obtain excellent acceptance and resolution data for K? nuclear capture on H, 4He, 9Be and 12C, both at-rest and in-flight. During the second half of 2012, a successful data taking was performed with a dedicated pure carbon target implemented in the central region of KLOE, providing a high statistic sample of pure at-rest K? nuclear interactions. For the future, dedicated setups involving cryogenic gaseous targets are under preparation.
A New Event Display for the KLOE-2 Experiment
W. Krzemień
abstract
In this contribution, we describe KNEDLE ? the new event display for the KLOE-2 experiment. The basic objectives and software requirements are presented. The current status of the development is given along with a short discussion of the future plans.
Ks semileptonic decays and test of CPT symmetry with the KLOE detector
D. Kamińska on behalf of the KLOE-2 Collaboration
abstract
Study of semileptonic decays of neutral kaons allows to perform a test of discrete symmetries, as well as basic principles of the Standard Model. In this paper, a general review on dependency between charge asymmetry constructed for semileptonic decays of short- and long-lived kaons and CPT symmetry is given.
Search for polarization effects in the antiproton production process
D. Grzonka, K. Kilian, J. Ritman, T. Sefzick, W. Oelert, M. Diermaier, E. Widmann, J. Zmeskal, B. Glowacz, P. Moskal, M. Zielinski, M. Wolke, P. Nadel-Turonski, M. Carmignotto, T. Horn, H. Mkrtchyan, A. Asaturyan, A. Mkrtchyan, V. Tadevosyan, S. Zhamkochyan, S. Malbrunot-Ettenauer, W. Eyrich, F. Hauenstein, A. Zink
abstract
For the production of a polarized antiproton beam various methods have been suggested including the possibility that antiprotons may be produced polarized which will be checked experimentally. The polarization of antiprotons produced under typical conditions for antiproton beam preparation will be measured at the CERN/PS. If the production process creates some polarization a polarized antiproton beam could be prepared by a rather simple modification of the antiproton beam facility. The detection setup and the expected experimental conditions are described.
Search for dark Higgsstrahlung in e+ e- -> mu+ mu- and missing energy events with the KLOE experiment
D. Babusci, ..., E. Czerwiński, A. Gajos, D. Kamińska, W. Krzemień, P. Moskal, M. Silarski, W. Wiślicki, et al.
abstract
We searched for evidence of a Higgsstrahlung process in a secluded sector, leading to a final state with a dark photon U and a dark Higgs boson h', with the KLOE detector at DAFNE. We investigated the case of h' lighter than U, with U decaying into a muon pair and h' producing a missing energy signature. We found no evidence of the process and set upper limits to its parameters in the range 2m_mu
Kaon Physics with the KLOE Detector
C. Bloise, E. De Lucia, A. De Santis, P. De Simone, E. Czerwiński, A. Gajos, D. Kamińska, P. Moskal, M. Silarski, A. Di Domenico, A. Passeri, W. Wiślicki
abstract
In this paper, we discuss the recent finalized analyses by the KLOE experiment at DA?NE: the CPT and Lorentz invariance test with entangled K0K0 pairs, and the precision measurement of the branching fraction of the decay K+ ? ?+???+(?). We also present the status of an ongoing analysis aiming to precisely measure the K? mass.
ABC Effect and Resonance Structure in the Double-Pionic Fusion to 3He
P. Adlarson, ..., E. Czerwiński, M. Hodana, W. Krzemień, P. Moskal, I. Ozerianska, M. Skurzok, M. Zielinski, et al.
abstract
Exclusive and kinematically complete measurements of the double pionic fusion to 3He have been performed in the energy region of the so-called ABC effect, which denotes a pronounced low-mass enhancement in the pi pi-invariant mass spectrum. The experiments were carried out with the WASA detector setup at COSY. Similar to the observations in the basic pn->dpi0pi0 reaction and in the dd->4Hepi0pi0 reaction, the data reveal a correlation between the ABC effect and a resonance-like energy dependence in the total cross section. Differential cross sections are well described by the hypothesis of d* resonance formation during the reaction process in addition to the conventional t-channel Delta Delta mechanism. The deduced d* resonance width can be understood from collision broadening due to Fermi motion of the nucleons in initial and final nuclei.
A novel method for the line-of-response and time-of-flight reconstruction in TOF-PET detectors based on a library of synchronized model signals
P. Moskal, N. Zoń, T. Bednarski, P. Białas, E. Czerwiński, A. Gajos, D. Kamińska, Ł. Kapłon, A. Kochanowski, G. Korcyl, J. Kowal, P. Kowalski, T. Kozik, W. Krzemień, E. Kubicz, Sz. Niedźwiecki, M. Pałka, L. Raczyński, Z. Rudy, O. Rundel, P. Salabura, N.G. Sharma, M. Silarski, A. Słomski, J. Smyrski, A. Strzelecki, A. Wieczorek, W. Wiślicki, M. Zieliński
abstract
A novel method of hit time and hit position reconstruction in scintillator detectors is described. The method is based on comparison of detector signals with results stored in a library of synchronized model signals registered for a set of well-defined positions of scintillation points. The hit position is reconstructed as the one corresponding to the signal from the library which is most similar to the measurement signal. The time of the interaction is determined as a relative time between the measured signal and the most similar one in the library. A degree of similarity of measured and model signals is defined as the distance between points representing the measurement- and model-signal in the multi-dimensional measurement space. Novelty of the method lies also in the proposed way of synchronization of model signals enabling direct determination of the difference between time-of-flights (TOF) of annihilation quanta from the annihilation point to the detectors. The introduced method was validated using experimental data obtained by means of the double strip prototype of the J-PET detector and 22Na sodium isotope as a source of annihilation gamma quanta.The detector was built out from plastic scintillator strips with dimensions of 5 mm x 19 mm x 300 mm, optically connected at both sides to photomultipliers,from which signals were sampled by means of the Serial Data Analyzer.Using the introduced method, the spatial and TOF resolution of about 1.3 cm (?) and 125 ps (?) were established, respectively.
Study of the polarization degree for the -> p p ->pp eta measurement with WASA
I. Ozerianska, P. Moskal, M. Hodana
abstract
Understanding of the production processes of the eta meson will strongly rely on the precise determination of spin observables. So far these observables have been determined only for few excess energies and with low statistics (Winter et al. Eur. Phys. J. A18, 355 2003; Czyzykiewicz et al. Phys. Rev. Lett. 98, 122003 2007; Balestra et al. Phys. Rev. C69, 064003 2004). In the year 2010 WASA detector was used for the measurement of the p?p?pp? reaction with the polarized proton beam of COSY (Moskal and Hodana J. Phys. Conf. Ser 295, 012080 2011). The measurement was done for the excess energy of Q = 15 MeV and Q = 72 MeV. In total about 106 events corresponding to the p?p?pp? reaction have been collected.
A direct test of T symmetry in the neutral K meson system with KsKl->pi l nu and Kl->3pi0 at the KLOE-2 experiment
A. Gajos on behalf of the KLOE-2 Collaboration
abstract
Quantum entanglement of K and B mesons allows for a direct experimental test
of time-reversal symmetry independent of CP violation. The T symmetry can
be probed by exchange of initial and final states in the reversible transitions be-
tween flavor and CP-definite states of the mesons which are only connected by
the T conjugation. While such a test was successfully performed by the BaBar
experiment with neutral B mesons, the KLOE-2 detector can probe T -violation
in the neutral kaons system by investigating the process with KS->pi l nu
and KL->3pi0 decays. Analysis of the latter is facilitated by a novel recon-
struction method for the vertex of KL->3pi 0 decay which only involves neutral
particles. Details of this new vertex reconstruction technique are presented as
well as prospects for conducting the direct T symmetry test at the KLOE-2
experiment.
Status of measurement of KS -> pi e nu branching ratio and lepton charge asymmetry with the KLOE detector
D. Kamińska on behalf of the KLOE-2 Collaboration
abstract
We present the current status of the analysis of about 1.7 billion K S K L pair
events collected at DAFNE with the KLOE detector to determine the branching
ratio of KS-> pi e nu decay and the lepton charge asymmetry. This sample is
? 4 times larger in statistics than the one used in a previous KLOE analysis,
allowing us to improve the accuracy of the measurement and of the related
tests of CPT symmetry and Delta S = Delta Q rule.
Study of Dalitz decay phi -> eta e+e- with KLOE detector
D. Babusci, ..., I. Balwierz-Pytko, E. Czerwiński, A. Gajos, D. Kamińska, P. Moskal, M. Silarski, W. Wiślicki, et al.
abstract
We have studied the vector to pseudoscalar conversion decay phi -> eta e+e-, with eta -> pi0pi0pi0, with the KLOE detector at DAPHNE. The data set of 1.7 fb-1 of e+e- collisions at sqrt(s)~Mphi contains a clear conversion decay signal of ~31,000 events from which we measured a value of BR(phi -> eta e+e-)=(1.075+-0.007+-0.038)x10-4. The same sample is used to determine the transition form factor by a fit to the e+e- invariant mass spectrum, obtaining b(phi eta) =(1.17 +- 0.10 + 0.07) GeV-2, that improves by a factor of five the precision of the previous measurement and is in good agreement with VMD expectations.
Measurement of the absolute branching ratio of the K+->pi+pi-pi+(gamma) decay with the KLOE detector
KLOE-2 Collaboration: D. Babusci, ..., I. Balwierz-Pytko, E. Czerwiński, A. Gajos, K. Kacprzak, D. Kamińska, P. Moskal, M. Silarski, W. Wiślicki et al.
abstract
The absolute branching ratio of the K+->pi+pi-pi+(gamma)decay, inclusive of final-state
radiation, has been measured using ?17 million tagged K + mesons collected with
the KLOE detector at DAFNE, the Frascati phi-factory. The result is:
BR(K+->pi+pi-pi+(gamma))= 0.05565 +- 0.00031stat +- 0.00025syst
a factor ~5 more precise with respect to the previous result. This work completes
the program of precision measurements of the dominant kaon branching ratios at
KLOE.
Measurement of the np->npi0i0 Reaction in Search for the Recently Observed d*(2380) Resonance
P. Adlarson,..., E. Czerwiński, M. Hodana, W. Krzemień, P. Moskal, I. Ozerianska, M. Skurzok, M. Zielinski, et al.
abstract
Exclusive measurements of the quasi-free np->nppi0pi0 reaction have been performed by means of dp collisions at Td = 2.27 GeV using the WASA detector setup at COSY. Total and differential cross sections have been obtained covering the energy region sqrt_s = (2.35 - 2.46) GeV, which includes the region of the ABC effect and its associated d*(2380) resonance. Adding the d* resonance amplitude to that for the conventional processes leads to a reasonable description of the data. The observed resonance effect in the total cross section is in agreement with the predictions of Faeldt and Wilkin as well Albadajedo and Oset. The ABC effect, {it i.e.} the low-mass enhancement in the pi0pi0-invariant mass spectrum, is found to be very modest - if present at all, which might pose a problem to some of its interpretations.
Experimental access to Transition Distribution Amplitudes with the PANDA experiment at FAIR
B.P. Singh,..., W. Krzemień, S. Jowzaee, B. Kamys, P. Moskal, A. Wrońska, P. Salabura, J. Smyrski, Z. Rudy,
abstract
We address the possibility of accessing nucleon-to-pion (?N) Transition Distribution Amplitudes (TDAs) from p?p?e+e??0 reaction with the future ={P}ANDA detector at the FAIR facility. At high center of mass energy and high invariant mass of the lepton pair q2, the amplitude of the signal channel p?p?e+e??0 admits a QCD factorized description in terms of ?N TDAs and nucleon Distribution Amplitudes (DAs) in the forward and backward kinematic regimes. Assuming the validity of this factorized description, we perform feasibility studies for measuring p?p?e+e??0 with the ={P}ANDA detector. Detailed simulations on signal reconstruction efficiency as well as on rejection of the most severe background channel, {it i.e.} p?p??+???0 were performed for the center of mass energy squared s=5 GeV2 and s=10 GeV2, in the kinematic regions 3.00.5 in the proton-antiproton center of mass frame. Results of the simulation show that the particle identification capabilities of the ={P}ANDA detector will allow to achieve a background rejection factor at the level of 108 (2?107) at low (high) q2 while keeping the signal reconstruction efficiency at around 40% and that a clean lepton signal can be reconstructed with the expected statistics corresponding to 2 fb?1 of integrated luminosity. The future measurement of the signal channel cross section with ={P}ANDA will provide a new test of perturbative QCD description of a novel class of hard exclusive reactions and will open the possibility of experimentally accessing ?N TDAs.
Neutron-Proton Scattering in the Context of the d*(2380) Resonance
P. Adlarson, ..., E. Czerwiński, M. Hodana, W. Krzemień, P. Moskal, I. Ozerianska, M. Skurzok, M. Zielinski, et al.
abstract
New data on quasifree polarized neutron-proton scattering, in the region of the recently observed d* resonance structure, have been obtained by exclusive and kinematically complete high-statistics measurements with WASA at COSY. This paper details the determination of the beam polarization, checks of the quasifree character of the scattering process, on all obtained Ay angular distributions and on the new partial-wave analysis, which includes the new data producing a resonance pole in the 3D3-3G3 coupled partial waves at (2380+-10-i40+-5) MeV -- in accordance with the d* dibaryon resonance hypothesis. The effect of the new partial-wave solution on the description of total and differential cross section data as well as specific combinations of spin-correlation and spin-transfer observables available from COSY-ANKE measurements at Td = 2.27 GeV is discussed.
Test of a single module of the J-PET scanner based on plastic scintillators
P. Moskal, Sz. Niedźwiecki, T. Bednarski, E. Czerwiński, Ł. Kapłon, E. Kubicz, I. Moskal, M. Pawlik-Niedźwiecka, N.G. Sharma, M. Silarski, M. Zieliński, N. Zoń, P. Białas, A. Gajos, A. Kochanowski, G. Korcyl, J. Kowal, P. Kowalski, T. Kozik, W. Krzemień, M. Molenda, M. Pałka, L. Raczyński, Z. Rudy, P. Salabura, A. Słomski, J. Smyrski, A. Strzelecki, A. Wieczorek, W. Wiślicki
abstract
Time of Flight Positron Emission Tomography scanner based on plastic scintillators is being developed at the Jagiellonian University by the J-PET collaboration. The main challenge of the conducted research lies in the elaboration of a method allowing application of plastic scintillators for the detection of low energy gamma quanta. In this article we report on tests of a single detection module built out from BC-420 plastic scintillator strip (with dimensions of 5x19x300mm^3) read out at two ends by Hamamatsu R5320 photomultipliers. The measurements were performed using collimated beam of annihilation quanta from the 68Ge isotope and applying the Serial Data Analyzer (Lecroy SDA6000A) which enabled sampling of signals with 50ps intervals. The time resolution of the prototype module was established to be better than 80ps (sigma) for a single level discrimination. The spatial resolution of the determination of the hit position along the strip was determined to be about 0.93cm (sigma) for the annihilation quanta. The fractional energy resolution for the energy E deposited by the annihilation quanta via the Compton scattering amounts to sigma(E)/E = 0.044/sqrt(E[MeV]) and corresponds to the sigma(E)/E of 7.5% at the Compton edge.
Novel method for hit-position reconstruction using voltage signals in plastic scintillators and its application to Positron Emission Tomography
L. Raczyński, P. Moskal, P. Kowalski, W. Wiślicki, T. Bednarski, P. Białas, E. Czerwiński, Ł. Kapłon, A. Kochanowski, G. Korcyl, J. Kowal, T. Kozik, W. Krzemień, E. Kubicz, M. Molenda, I. Moskal, Sz. Niedźwiecki, M. Pałka, M. Pawlik-Niedźwiecka, Z. Rudy, P. Salabura, N.G. Sharma, M. Silarski, A. Słomski, J. Smyrski, A. Strzelecki, A. Wieczorek, M. Zieliński, N. Zoń
abstract
Currently inorganic scintillator detectors are used in all commercial Time of Flight Positron Emission Tomograph (TOF-PET) devices. The J-PET collaboration investigates a possibility of construction of a PET scanner from plastic scintillators which would allow for single bed imaging of the whole human body. This paper describes a novel method of hit-position reconstruction based on sampled signals and an example of an application of the method for a single module with a 30 cm long plastic strip, read out on both ends by Hamamatsu R4998 photomultipliers. The sampling scheme to generate a vector with samples of a PET event waveform with respect to four user-defined amplitudes is introduced. The experimental setup provides irradiation of a chosen position in the plastic scintillator strip with an annihilation gamma quanta of energy 511 keV. The statistical test for a multivariate normal (MVN) distribution of measured vectors at a given position is developed, and it is shown that signals sampled at four thresholds in a voltage domain are approximately normally distributed variables. With the presented method of a vector analysis made out of waveform samples acquired with four thresholds, we obtain a spatial resolution of about 1 cm and a timing resolution of about 80 ps (sigma).
Charge Symmetry Breaking in dd->4Hepi0 with WASA-at-COSY
P. Adlarson, ..., E. Czerwiński, M. Hodana, W. Krzemień, P. Moskal, I. Ozerianska, M. Skurzok, M. Zielinski, et al.
abstract
Charge symmetry breaking (CSB) observables are a suitable experimental tool to examine effects induced by quark masses on the nuclear level. Previous high precision data from TRIUMF and IUCF are currently used to develop a consistent description of CSB within the framework of chiral perturbation theory. In this work the experimental studies on the reaction dd->4He{pi}0 have been extended towards higher excess energies in order to provide information on the contribution of p-waves in the final state. For this, an exclusive measurement has been carried out at a beam momentum of p=1.2 GeV/c using the WASA-at-COSY facility. The total cross section amounts to sigma(tot) = (118 +- 18(stat) +- 13(sys) +- 8(ext)) pb and first data on the differential cross section are consistent with s-wave pion production.
Cross section ratio and angular distributions of the reaction p + d -> (3)He + eta at 48.8 MeV and 59.8 MeV excess energy
P. Adlarson, E. Czerwiński, M. Hodana, W. Krzemień, P. Moskal, I. Ozerianska, M. Skurzok, M. Zielinski, et al.
abstract
We present new data for angular distributions and on the cross section ratio of the p+d -> (3)He + eta reaction at excess energies of Q = 48.8 MeV and Q = 59.8 MeV. The data have been obtained at the WASA-at-COSY experiment (Forschungszentrum Jülich) using a proton beam and a deuterium pellet target. While the shape of obtained angular distributions show only a slow variation with the energy, the new results indicate a distinct and unexpected total cross section fluctuation between Q = 20 MeV and Q = 60 MeV, which might indicate the variation of the production mechanism within this energy interval.
Validation of Spallation Models for p+Al Reactions at 180 MeV Incident Proton Beam Energy
S. Sharma, B. Kamys, F. Goldenbaum, D. Filges
abstract
Various observables measured at low beam energy of 180 MeV for proton induced reactions on 27 Al targets have been compared with theoretical predictions of different spallation models. These models assume that the reactions proceed in two stages: the intranuclear cascade of nucleon?nucleon collisions followed by the de-excitation of equilibrated, excited remnants of the cascade. The calculations of the intranuclear cascade were performed by means of the INCL4.6 code, whereas the second stage of the reactions was realized using four different models: ABLA07, GEMINI++, GEM2, and SMM. It was found that the main properties of the experimental isobaric total production cross sections are reasonably well reproduced by all these spallation models. The shape of the energy averaged angular distributions of ejectiles with A = 7, 12, 16, 22, 24, and 25 was also well described by the models listed above, however the absolute magnitude of A = 7 and A = 25 data is strongly underestimated and overestimated, respectively. The theoretical energy spectra for A = 7, A = 16, and A = 22 are very similar for all the models and reproduce well the data for heavier ejectiles, whereas the A = 7 data deviate from the model cross sections for energies smaller than ? 10 MeV what may indicate the presence of a reaction mechanism not included in the spallation models. The following ranking of the four used models ? all of them being coupled to the very same INCL4.6 INC model ? was determined using the statistical H-test in a quantitative analysis: (1) GEMINI++, (2) SMM, (3) ABLA07, and (4) GEM2.
Measurement of the eta -> pi + pi - pi0 Dalitz plot distribution
P. Adlarson,..., E. Czerwiński, M. Hodana, W. Krzemień, P. Moskal, I. Ozerianska, M. Skurzok, M. Zieliński, et al.
abstract
Dalitz plot distribution of the eta-> pi+pi-pi0 decay is determined using a data sample of 1.2*10^7 eta mesons from pd->3He eta reaction at 1 GeV collected by the WASA detector at COSY.
Sequential and simultaneous emission of particles from p + Al collisions at GeV energies
M. Fidelus,.., B. Kamys, Z. Rudy, S. Sharma et al.,
abstract
The energy and angular dependence of double differential cross sections
d
2
?/ddE
were measured for
p
,
d
,
t
,
3
,
4
,
6
He,
6
,
7
,
8
,
9
Li,
7
,
9
,
10
Be, and
10
,
11
B produced in collisions of 1.2, 1.9, and 2.5 GeV protons with an Al
target. It was found that the cross sections are almost independent of the beam energy. The spectra and angular
distributions indicate a presence of two contributions: a quasi-isotropic, low-energy one which is attributed
to the emission of particles from excited remnants of the intranuclear cascade, and an anisotropic part which
is interpreted to originate from the first stage of the reaction. The experimental data are compared with an
intranuclear cascade model coupled to evaporation, and to statistical multifragmentation models using their
standard parameter settings. It was found that all applied models produce very similar results describing spectra
of the intermediate mass fragments. All models also reproduce well the low-energy part of the spectra of light
charged particles (below?30 MeV). The description of the higher energy part (50?150 MeV) of the light
charged particles spectra is poorer, deteriorating with decreasing scattering angle and decreasing mass of the
particles.
Evidence for a New Resonance from Polarized Neutron-Proton Scattering
P. Adlarson, ..., E. Czerwiński, M. Hodana, J. Klaja, W. Krzemień, P. Moskal, I. Ozerianska, M. Skurzok, M. Zieliński et al.
abstract
Exclusive and kinematically complete high-statistics measurements of quasifree polarized vec_n p scattering have been performed in the energy region of the narrow resonance structure d* with I(JP)=0(3+), M ~2380 MeV/c2 and Gamma 70 MeV observed recently in the double-pionic fusion channels pn->dpi0pi0 and pn->dpi+pi-. The experiment was carried out with the WASA detector setup at COSY having a polarized deuteron beam impinged on the hydrogen pellet target and utilizing the quasifree process d p->np+p_spectator. That way the np analyzing power Ay was measured over a large angular range. The obtained Ay angular distributions deviate systematically from the current SAID SP07 NN partial-wave solution. Incorporating the new Ay data into the SAID analysis produces a pole in the 3D3->3G3 waves as expected from the d* resonance hypothesis.
Dependence and Influence of Projectile Energy and Target Mass on the Production of Light Charged Particles and Intermediate Mass Fragments in Proton Induced Reactions
S. Sharma, D. Filges, F. Goldenbaum, B. Kamys
abstract
Calculations were performed for proton induced spallation reactions over a wide range of atomic masses on the targets: 12C, 27Al, natNi, 108Ag and 197Au using an Intra-nuclear Cascade Model (INCL4.6) with coalescence which includes the emission of protons, light clusters (d?4He), and intermediate mass fragments (up to A=8) formed by the nucleons during the first stage of the reaction. The emission of particles from excited cascade residua are described using three different theoretical models SMM, ABLA07, and GEMINI++. A comparison of calculations with experimental double differential cross?sections for light charged particles and selected intermediate mass fragments was studied at proton beam energies from GeV. Systematic deviations of the simulated cross sections from the experimental data were found for both light charged particles and intermediate mass fragments.
Search for light vector boson production in e+e- -> mi+mi- gamma interactions with the KLOE experiment
D. Babusci, I. Balwierz-Pytko, E. Czerwiński, A. Gajos, D. Kamińska, W. Krzemień, P. Moskal, M. Silarski, J. Zdebik, et al.
abstract
We have searched for a light vector boson U, the possible carrier of a dark force, with the KLOE detector at the DAFNE e+e- collider, motivated by the astrophysical evidence for the presence of dark matter in the universe. Using e+e- collisions collected for an integrated luminosity of 239.3~pb?1, we look for a dimuon mass peak in the reaction e+e- -> mu+mu-gamma, corresponding to the decay U->mu+mu-. We find no evidence for a U vector boson signal. We set a 90% CL upper limit for the mixing parameter squared between the photon and the U boson of 1.6×10^5 to 8.6×10^7 for the mass region 520
Determination of the eta prime - proton scattering length in free space
E. Czerwiński, P. Moskal, M. Silarski, S. D. Bass, D. Grzonka, B. Kamys, A. Khoukaz, J. Klaja, W. Krzemień, W. Oelert, J. Ritman, T. Sefzick, J. Smyrski, A. Täschner, M. Wolke, M. Zieliński
abstract
Taking advantage of both the high mass resolution of the COSY--11 detector and the high energy resolution of the low-emittance proton-beam of the Cooler Synchrotron COSY we determine the excitation function for the pp --> pp eta' reaction close-to-threshold. Combining these data with previous results we extract the scattering length for the eta'-proton potential in free space to be Re (a p eta') = 0 +/- 0.43 fm and Im a_(p eta') = 0.37^{+0.40}_{-0.16} fm.
Computing support for advanced medical data analysis and imaging
W. Wiślicki, T. Bednarski, P. Białas, E. Czerwiński, Ł. Kapłon, A. Kochanowski, G. Korcyl, J. Kowal, P. Kowalski, T. Kozik, W. Krzemień, M. Molenda, P. Moskal, S. Niedźwiecki, M. Pałka, M. Pawlik, L. Raczyński, Z. Rudy, P. Salabura, N.G. Sharma, M. Silarski, A. Słomski, J. Smyrski, A. Strzelecki, A. Wieczorek, M. Zieliński, N. Zoń
abstract
We discuss computing issues for data analysis and image reconstruction of PET-TOF medical scanner or other medical scanning devices producing large volumes of data. Service architecture based on the grid and cloud concepts for distributed processing is proposed and critically discussed.
A novel method based solely on FPGA units enabling measurement of time and charge of analog signals in Positron Emission Tomography
M. Pałka, T. Bednarski, P. Białas, E. Czerwiński, Ł. Kapłon, A. Kochanowski, G. Korcyl, J. Kowal, P. Kowalski, T. Kozik, W. Krzemień, M. Molenda, P. Moskal, Sz. Niedźwiecki, M. Pawlik, L. Raczyński, Z. Rudy, P. Salabura, N.G. Sharma, M. Silarski, A. Słomski, J. Smyrski, A. Strzelecki, W. Wiślicki, M. Zieliński, N. Zoń
abstract
This article presents a novel technique for precise measurement of time and charge based solely on FPGA (Field Programmable Gate Array) device and few satellite discrete electronic components used in Positron Emission Tomography (PET). Described approach simplifies electronic circuits, reduces the power consumption, lowers costs, merges front-end electronics with digital electronics and also makes more compact final design. Furthermore, it allows to measure time when analog signals cross a reference voltage at different threshold levels with a very high precision of ? 10ps (rms) and thus enables sampling of signals in a voltage domain.
A novel method for calibration and monitoring of time synchronization of TOF-PET scanners by means of cosmic rays
M. Silarski, E. Czerwiński, T. Bednarski, P. Moskal, P. Białas, Ł. Kapłon, A. Kochanowski, G. Korcyl, J. Kowal, P. Kowalski, T. Kozik, W. Krzemień, M. Molenda, Sz. Niedźwiecki, M. Pałka, M. Pawlik, L. Raczyński, Z. Rudy, P. Salabura, N.G. Sharma, A. Słomski, J. Smyrski, A. Strzelecki, W. Wiślicki, M. Zieliński, N. Zoń
abstract
All of the present methods for calibration and monitoring of TOF-PET scanner detectors utilize radioactive isotopes such as e.g. 22Na or 68Ge, which are placed or rotate inside the scanner. In this article we describe a novel method based on the cosmic rays application to the PET calibration and monitoring methods. The concept allows to overcome many of the drawbacks of the present methods and it is well suited for newly developed TOF-PET scanners with a large longitudinal field of view. The method enables also monitoring of the quality of the scintillator materials and in general allows for the continuous quality assurance of the PET detector performance.
3D PET image reconstruction based on the maximum likelihood estimation method (MLEM) algorithm
A. Słomski, Z. Rudy, T. Bednarski, P. Białas, E. Czerwiński, Ł. Kapłon, A. Kochanowski, G. Korcyl, J. Kowal, P. Kowalski, T. Kozik, W. Krzemień, M. Molenda, P. Moskal, Sz. Niedźwiecki, M. Pałka, M. Pawlik, L. Raczyński, P. Salabura, N. G. Sharma, M. Silarski, J. Smyrski, A. Strzelecki, W. Wiślicki, M. Zieliński, N. Zoń
abstract
A positron emission tomography (PET) scan does not measure an image directly. Instead, a PET scan measures a sinogram at the boundary of the field-of-view that consists of measurements of the sums of all the counts along the lines connecting the two detectors. Because there is a multitude of detectors built in a typical PET structure, there are many possible detector pairs that pertain to the measurement. The problem is how to turn this measurement into an image (this is called imaging). Significant improvement in PET image quality was achieved with the introduction of iterative reconstruction techniques. This was realized approximately 20 years ago (with the advent of new powerful computing processors). However, three-dimensional imaging still remains a challenge. The purpose of the image reconstruction algorithm is to process this imperfect count data for a large number (many millions) of lines of response and millions of detected photons to produce an image showing the distribution of the labeled molecules in space.
Trigger-less and reconfigurable data acquisition system for positron emission tomography
G. Korcyl, P. Moskal, T. Bednarski, P. Białas, E. Czerwiński, Ł. Kapłon, A. Kochanowski, J. Kowal, P. Kowalski, T. Kozik, W. Krzemień, M. Molenda, Sz. Niedźwiecki, M. Pałka, M. Pawlik, L. Raczyński, Z. Rudy, P. Salabura, N. G. Sharma, M. Silarski, A. Słomski, J. Smyrski, A. Strzelecki, W. Wiślicki, M. Zieliński, N. Zoń
abstract
This article is focused on data acquisition system (DAQ) designed especially to be used in positron emission tomography (PET) or single-photon emission computed tomography. The system allows for continuous registration of analog signals during measurement. It has been designed to optimize registration and processing of the information carried by signals from the detector system in PET scanner. The processing does not require any rejection of data with a trigger system. The proposed system possesses also an ability to implement various data analysis algorithms that can be performed in real time during data collection.
Determination of the map of efficiency of the Jagiellonian Positron Emission Tomograph (J-PET) detector with the GATE package
P. Kowalski, L. Raczyński, T. Bednarski, P. Białas, E. Czerwiński, K. Giergiel, Ł. Kapłon, A. Kochanowski, G. Korcyl, J. Kowal, T. Kozik, W. Krzemień, M. Molenda, I. Moskal, P. Moskal, Sz. Niedźwiecki, M. Pałka, M. Pawlik-Niedźwiecka, Z. Rudy, P. Salabura, N.G. Sharma, M. Silarski, A. Słomski, J. Smyrski, A. Strzelecki, K. Szymański, W. Wiślicki, P. Witkowski, M. Zieliński, N. Zoń
abstract
A novel PET detector consisting of strips of polymer scintillators is being developed by the J-PET Collaboration. The map of efficiency and the map of geometrical acceptance of the 2-strip J-PET scanner are presented. Map of efficiency was determined using the Monte Carlo simulation software GATE based on GEANT4. Both maps were compared using method based on the chi2 test.
Few-body aspects of the near threshold pseudoscalar meson production
P. Moskal
abstract
During last decade large samples of data have been collected on the production of the ground-state pseudoscalar mesons in collisions of proton or deuteron beam with hydrogen or deuterium target. These measurements have been performed in the vicinity of the kinematical threshold for meson production where only a few partial waves in both initial and final state are expected to contribute to the production process. This simplifies significantly the interpretation of the data, yet still appears to be challenging due to the three or four particle final state systems with a complex hadronic potential. We review experiments and phenomenology of the near threshold production of the ground-state mesons in the few-body final states as for example: nucleus-meson and nucleon-nucleon-meson, and report on the status of the search of the mesic-nuclei (a meson-nucleus bound states). Experimental advantages of measurements close to the kinematical threshold are discussed, and general features of the production mechanism of the eta and eta prime mesons in the nucleon-nucleon collisions are presented emphasising results of measurements of spin and izospin dependence of the production cross sections.
Plastic scintillators for positron emission tomography obtained by the bulk polymerization method
Ł. Kapłon, A. Kochanowski, M. Molenda, P. Moskal, A. Wieczorek, T. Bednarski, P. Białas, E. Czerwiński, G. Korcyl, J. Kowal, P. Kowalski, T. Kozik, W. Krzemień, Sz. Niedźwiecki, M. Pałka, M. Pawlik, L. Raczyński, Z. Rudy, P. Salabura, N. G. Sharma, M. Silarski, A. Słomski, J. Smyrski, A. Strzelecki, W. Wiślicki, M. Zieliński, N. Zoń
abstract
This paper describes three methods regarding the production of plastic scintillators. One method appears to be suitable for the manufacturing of plastic scintillators, revealing properties which fulfill the requirements of novel positron emission tomography scanners based on plastic scintillators. The key parameters of the manufacturing process are determined and discussed.
J-PET analysis framework for the prototype TOF-PET detector
W. Krzemień, M. Silarski, K. Stola, D. Trybek, T. Bednarski, P. Białas, E. Czerwiński, Ł. Kapłon, A. Kochanowski, G. Korcyl, J. Kowal, P. Kowalski, T. Kozik, M. Molenda, P. Moskal, Sz. Niedźwiecki, M. Pałka, M. Pawlik, L. Raczyński, Z. Rudy, P. Salabura, N.G. Sharma, A. Słomski, J. Smyrski, A. Strzelecki, W. Wiślicki, M. Zieliński, N. Zoń
abstract
Novel TOF-PET scanner solutions demand, apart from the state of the art detectors, software for fast processing of the gathered data, monitoring of the whole scanner and reconstruction of the PET image. In this article we present an analysis framework for the novel STRIP-PET scanner developed by the J-PET collaboration in the Institute of Physics of the Jagiellonian University. This software is based on the ROOT package used in many particle physics experiments.
Database and data structure for the novel TOF-PET detector developed for J-PET project
E. Czerwiński, M. Zieliński, T. Bednarski, P. Białas, Ł. Kapłon, A. Kochanowski, G. Korcyl, J. Kowal, P. Kowalski, T. Kozik, W. Krzemień, E. Kubicz, M. Molenda, P. Moskal, Sz. Niedźwiecki, M. Pałka, M. Pawlik, L. Raczyński, Z. Rudy, P. Salabura, N. G. Sharma, M. Silarski, A. Słomski, J. Smyrski, A. Strzelecki, A. Wieczorek, W.Wiślicki, N. Zoń
abstract
The complexity of the hardware and the amount of data collected during the PET imaging process require application of modern methods of efficient data organization and processing. In this article we will discuss the data structures and the flow of collected data from the novel TOF-PET medical scanner which is being developed at the Jagiellonian University. The developed data format reflects: registration process of the gamma quanta emitted from positron-electron annihilation, Front-End Electronic (FEE) structure and required input information for the image reconstruction. In addition, the system database fulfills possible demands of the evolving J-PET project.
Calibration of photomultipliers gain used in the J-PET detector
T. Bednarski, E. Czerwiński, P. Moskal, P. Białas, K. Giergiel, Ł. Kapłon, A. Kochanowski, G. Korcyl, J. Kowal, P. Kowalski, T. Kozik, W. Krzemień, M. Molenda, I. Moskal, Sz. Niedźwiecki, M. Pałka, M. Pawlik, L. Raczyński, Z. Rudy, P. Salabura, N.G. Sharma, M. Silarski, A. Słomski, J. Smyrski, A. Strzelecki, K. Szymański, W. Wiślicki, P. Witkowski, M. Zieliński, N. Zoń
abstract
Photomultipliers are commonly used in commercial PET scanner as devices which convert light produced in scintillator by gamma quanta from positron-electron annihilation into electrical signal. For proper analysis of obtained electrical signal, a photomultiplier gain curve must be known, since gain can be significantly different even between photomultipliers of the same model. In this article we describe single photoelectron method used for photomultipliers calibration applied for J-PET scanner, a novel PET detector being developed at the Jagiellonian University. Description of calibration method, an example of calibration curve and gain of few R4998 Hamamatsu photomultipliers are presented.
Study of the eta meson production with polarized proton beam
M. Hodana, P. Moskal, I. Ozerianska, M. Zieliński
abstract
The pp-> pp eta reaction was investigated at excess energies of 15 MeV and 72 MeV using the azimuthally symmetric WASA detector and a polarized proton beam of the Cooler Synchrotron COSY. The aim of the studies is the determination of partial wave contributions to the production process of the eta meson in nucleon-nucleon collisions. Here we present preliminary results of the extraction of the position of the interaction region with respect to the WASA detector and preliminary results on the degree of polarization of the COSY proton beam used in the experiment.
Search for the manifestation of the mesic-nuclei on the dd-->3HeNpi excitation function measured with WASA-at-COSY
W. Krzemień, P. Moskal, M. Skurzok
abstract
We search for an evidence of eta-mesic 4He with the WASA-at-COSY detector. Two dedicated experiments were performed at the Cooler Synchrotron COSY-Juelich. The experimental method is based on the measurement of the excitation functions for the two reaction channels: dd-->3Heppi- and dd-->3Henpi0, where the outgoing N-pi pairs originate from the conversion of the eta meson on a nucleon inside the He nucleus. In this contribution, the experimental method is shortly described and preliminary excitation functions from the 2010 data are presented.
Study of the N N eta' production with COSY-11
E. Czerwiński, P. Moskal, M. Silarski
abstract
We describe a new high precision measurement of the production cross-section for the eta' meson in proton-proton collisions for five beam momenta at low access energy region Q conducted at the COSY-11 detection system together with an updated results of all other previous measurements of cross-section for (pp-->pp eta') at COSY-11.
Search for eta-Mesic 4He with WASA-at-COSY
W. Krzemien, P. Moskal, M. Skurzok
abstract
An exclusive measurement of the excitation functions for the dd ->3He p ?- and dd -> 3He n ?0 -> 3He n gamma gamma reactions was performed at the Cooler Synchrotron COSY-Juelich with the WASA-at-COSY detection system. The data were collected in two dedicated experiments in 2008 and in 2010. The experimental method and the current status of the analysis are presented.
Studies of Mesic Nuclei via Decay Reactions
S. Wycech, W. Krzemień
abstract
Collisions in a system of two particles at energies close to a bound state in different channels are discussed. Next, the bound state decays into a third coupled channel. A phenomenological approach to dd->pi-p3He reaction is presented.
COSY Proposal/Beam Request: Search for the eta -mesic 3He with WASA at COSY
P. Moskal, W. Krzemien, M. Skurzok
abstract
We propose to conduct a search for the 3He-eta bound state by the energy scan at the final states ppNpi, 3He6gamma and 3He2gamma measuring excitation functions of its production cross section in proton-deuteron reactions for processes corresponding to two anticipated mechanisms: (i) absorption of the eta meson by one of the nucleons, which subsequently decays into N-pi pair e.g.: pd-> (3He-eta)bound ->ppppi- , and (ii) decay of the eta-meson while it is still orbiting around a nucleus e.g.: pd-> (3He-eta)bound -> 3He6gamma reactions. This sproposal has been accepted in PAC Session No. 42 II/2013 and experiment (Exp. No. 186.3) was carried out in May 2014.
List-mode reconstruction in 2D strip PET
P. Białas, J. Kowal, A. Strzelecki, T. Bednarski, E. Czerwiński, K. Giergiel, Ł. Kapłon, A. Kochanowski, G. Korcyl, P. Kowalski, T. Kozik, W. Krzemień, M. Molenda, I. Moskal, P. Moskal, S. Niedźwiecki, M. Pałka, M. Pawlik, L. Raczyński, Z. Rudy, P. Salabura, N.G. Sharma, M. Silarski, A. Słomski, J. Smyrski, K. Szymański, W. Wiślicki, P. Witkowski, M. Zieliński, N. Zoń
abstract
Using a theory of list-mode maximum likelihood
expectation-maximization (MLEM) algorithm, in this contribution,
we present a derivation of the system response
kernel for a novel positron emission tomography (PET)
detector based on plastic scintillators.
Phenomenology of the ppK+K- System Near Threshold
M. Silarski
abstract
In this article studies of the near threshold pp->ppK+K- reaction conducted with the COSY-11 and the ANKE detectors are reviewed. In particular recent investigations on the K+K? final state interaction are revisited taking into account updated cross sections of the COSY-11 experiment. These studies resulted in the new value of K+K- effective range amounting to: Re(bK+K-)=?0.2+0.8stat +0.4sys?0.6stat ?0.4sys fm and Im(bK+K?)=1.2 +0.5stat +0.3sys ?0.3stat ?0.3sys fm. The determined real and imaginary parts of the K+K? scattering length were estimated to be: |Re(aK+K-)|=10 +17stat ?10stat fm and Im(aK+K?)=0 +37stat ?10stat fm.
Test of CPT and Lorentz symmetry in entangled neutral kaons with the KLOE experiment
D. Babusci, ..., I. Balwierz-Pytko, E. Czerwiński, A. Gajos, K. Kacprzak, D. Kamińska, P. Moskal, M. Silarski, W. Wiślicki, J. Zdebik et al.
abstract
Neutral kaon pairs produced in phi decays in anti-symmetric entangled state can be exploited to search for violation of CPT symmetry and Lorentz invariance. We present an analysis of the CP-violating process phi->K_S K_L->pi+pi-pi+pi- based on 1.7 fb-1 of data collected by the KLOE experiment at the Frascati phi-factory DAFNE. The data are used to perform a measurement of the CPT-violating parameters Delta_amu for neutral kaons in the contest of the Standard Model Extension framework. The parameters measured in the reference frame of the fixed stars are: Delta_ao = (-6.0 +- 7.7_{stat} +- 3.1_{syst}) x 10^{-18} GeV Delta_ax = ( 0.9 +- 1.5_{stat} +- 0.6_{syst}) x 10^{-18} GeV Delta_ay = (-2.0 +- 1.5_{stat} +- 0.5_{syst}) x 10^{-18} GeV Delta_az = ( 3.1 +- 1.7_{stat} +- 0.5_{syst}) x 10^{-18} GeV These are presently the most precise measurements in the quark sector of the Standard Model Extension.
GASTONE64: A new front-end ASIC for the cylindrical GEM Inner Tracker of KLOE-2 experiment at DAFNE
A. Balla, E. Czerwiński, et al.
abstract
GASTONE64 (Gem Amplifier Shaper Tracking ON Events) is a novel 64-channel mixed analog-digital ASIC developed to readout the cylindrical GEM inner tracking detector of the KLOE-2 apparatus at the e+e?DA?NEDA?NE collider. It has been designed in the CMOS View the MathML source0.35?m technology and each analog channel is made of preamplifier, shaper and discriminator. The expected input charge ranges between few fC up to 40 fC, the charge sensitivity is 16 mV/fC while the equivalent input noise charge (ENC) is 800 e?+40 e?/pF. The discriminated signals are read-out using a 100 MBit/s LVDS serial data link. The power consumption is about 6 mW/channel.
Simulations of gamma quanta scattering in a single module of the J-PET detector
K. Szymański, P. Moskal, T. Bednarski, P. Białas, E. Czerwiński, K. Giergiel, Ł. Kapłon, A. Kochanowski, G. Korcyl, J. Kowal, P. Kowalski, T. Kozik, W. Krzemień, M. Molenda, I. Moskal, Sz. Niedźwiecki, M. Pałka, M. Pawlik, L. Raczyński, Z. Rudy, P. Salabura, N.G. Sharma, M. Silarski, A. Słomski, J. Smyrski, A. Strzelecki, P. Witkowski, W. Wiślicki, M. Zieliński, N. Zoń
abstract
This article describes simulations of scattering of annihilation gamma quanta in a strip of plastic scintillator. Such strips constitute basic detection modules in a newly proposed Positron Emission Tomography which utilizes plastic scintillators instead of inorganic crystals. An algorithm simulating chain of Compton scatterings was elaborated and series of simulations have been conducted for the scintillator strip with the cross section of 5 mm x 19 mm. Obtained results indicate that secondary interactions occur only in the case of about 8% of events and out of them only 25% take place in the distance larger than 0.5 cm from the primary interaction. It was also established that light signals produced at primary and secondary interactions overlap with the delay which distribution is characterized by FWHM of about 40 ps.
Application of WLS strips for position determination in Strip PET tomograph based on plastic scintillators
J. Smyrski, P. Moskal, T. Bednarski, P. Białas, E. Czerwiński, Ł. Kapłon, A. Kochanowski, G. Korcyl, J. Kowal, P. Kowalski, T. Kozik, W. Krzemień, M. Molenda, Sz. Niedźwiecki, M. Pałka, M. Pawlik, L. Raczyński, Z. Rudy, P. Salabura, N.G. Sharma, M. Silarski, A. Słomski, A. Strzelecki, W. Wiślicki, M. Zieliński, N. Zoń
abstract
A method of determination of a gamma quantum absorption point in a plastic scintillator block using a matrix of wavelength-shifting (WLS) strips is proposed. Application of this method for improvement of position resolution in newly proposed PET detectors based on plastic scintillators is presented. The method enables to reduce parallax errors in reconstruction of images which occurs in the presently used Positron Emission Tomography scanners.
Phenomenological Studies of the Low Energy Dynamics in the pp K+K- System
M. Silarski
abstract
In this article we review studies of the near threshold pp ? ppK + K ? reaction done with the COSY-11 and ANKE detectors. We discuss phenomenological studies of the ppK + K ? dynamics, in particular the recent investigations on the K + K ? final state interaction are presented.
Combined analysis of the K+K- interaction using near threshold pp-> ppK+K- data
M. Silarski, P. Moskal
abstract
The K+K? final state interaction was investigated based on both the K+K? invariant mass distributions measured at excess energies of Q=10 and 28 MeV and the near threshold excitation function for the pp?ppK+K? reaction. The K+K? final state enhancement factor was parametrized using the effective range expansion. The effective range of the K+K? interaction was estimated to be Re(bK+K?)=?0.1?0.4stat?0.3sys fm and Im(bK+K?)=1.2?0.2stat?0.0sys+0.1stat+0.2sys fm, and the determined real and imaginary parts of the K+K? scattering length amount to |Re(aK+K?)|=8.0?4.0stat+6.0stat fm and Im(aK+K?)=0.0?5.0stat+20.0stat fm.
Measurement of the pn->pp pi0pi- Reaction in Search for the Recently Observed Resonance Structure in dpi0pi0 and dpi+pi-systems
P. Adlarson, ..., E. Czerwiński, M. Hodana, J. Klaja, W. Krzemień, P. Moskal, I. Ozerianska, M. Skurzok, M. Zieliński et al.
abstract
Exclusive measurements of the quasi-free $pn o pppi^0pi^-$ reaction have been performed by means of $pd$ collisions at $T_p$ = 1.2 GeV using the WASA detector setup at COSY. Total and differential cross sections have been obtained covering the energy region $sqrt s$ = (2.35 - 2.46) GeV, which includes the region of the ABC effect and its associated resonance structure. No ABC effect, {it i.e.} low-mass enhancement is found in the $pi^0pi^-$-invariant mass spectrum -- in agreement with the constraint from Bose statistics that the isovector pion pair can not be in relative s-wave. At the upper end of the covered energy region $t$-channel processes for Roper, $Delta(1600)$ and $DeltaDelta$ excitations provide a reasonable description of the data, but at low energies the measured cross sections are much larger than predicted by such processes. Adding a resonance amplitude for the resonance at $m$=~2.37 GeV with $Gamma$ =~70 MeV and $I(J^P)=~0(3^+)$ observed recently in $pn o dpi^0pi^0$ and $pn o dpi^+pi^-$ reactions leads to an agreement with the data also at low energies.
A new limit on the CP violating decay KS -> 3pi0 with the KLOE experiment
D. Babusci, ..., I. Balwierz-Pytko, E. Czerwiński, P. Moskal, M. Silarski, W. Wiślicki, J. Zdebik et al.
abstract
We have carried out a new direct search for the CP violating decay KS -> 3pi0 with 1.7 fb^-1 of e+e- collisions collected by the KLOE detector at the phi-factory DAFNE. We have searched for this decay in a sample of about 5.9 x 10^8 KS KL events tagging the KS by means of the KL interaction in the calorimeter and requiring six prompt photons. With respect to our previous search, the analysis has been improved by increasing of a factor four the tagged sample and by a more effective background rejection of fake KS tags and spurious clusters. We find no candidates in data and simulated background samples, while we expect 0.12 standard model events. Normalizing to the number of KS -> 2pi0 events in the same sample, we set the upper limit on BR(KS -> 3pi0 < 2.6 x 10^-8 at 90% C.L., five times lower than the previous limit. We also set the upper limit on the eta_000 parameter, |eta_000 | < 0.0088 at 90% C.L., improving by a factor two the latest direct measurement.
Isospin decomposition of the basic double-pionic fusion in the region of the ABC effect
P. Adlarson, W. Augustyniak, W. Bardan, M. Bashkanov, T. Bednarski, FS. Bergmann, M. Berlowski, H. Bhatt, M. Buscher, H. Calen, H. Clement, D. Coderre, E. Czerwinski, K. Demmich, E. Doroshkevich, R. Engels, W. Erven, W. Eyrich, P. Fedorets, K. Fohl, K. Fransson, F. Goldenbaum, P. Goslawski, A. Goswami, K. Grigoryev, CO. Gullstrom, F. Hauenstein, L. Heijkenskjold, V. Hejny, F. Hinterberger, M. Hodana, B. Hoistad, A. Jany, BR. Jany, L. Jarczyk, T. Johansson, B. Kamys, G. Kemmerling, FA. Khan, A. Khoukaz, S. Kistryn, J. Klaja, H. Kleines, B. Klos, M. Krapp, W. Krzemien, P. Kulessa, A. Kupsc, K. Lalwani, D. Lersch, L. Li, B. Lorentz, A. Magiera, R. Maier, P. Marciniewski, B. Marianski, M. Mikirtychiants, HP. Morsch, P. Moskal, BK. Nandi, S. Niedzwiecki, H. Ohm, I. Ozerianska, EP. del Rio, P. Plucinski, P. Podkopal, et al.
abstract
Exclusive and kinematically complete high-statistics measurements of the basic double-pionic fusion reactions pn -> d pi(0)pi(0), pn -> d pi(+)pi(-) and pp -> d pi(+)pi(0) have been carried out simultaneously over the energy region of the ABC effect using the WASA detector setup at COSY. Whereas the isoscalar reaction part given by the d pi(0)pi(0) channel exhibits the ABC effect, i.e. a low-mass enhancement in the pi pi-invariant mass distribution, as well as the associated resonance structure in the total cross section, the isovector part given by the d pi(+)pi(0) channel shows a smooth behavior consistent with the conventional t-channel Delta Delta process. The d pi(+)pi(-) data are very well reproduced by combining the data for isovector and isoscalar contributions, if the kinematical consequences of the isospin violation due to different masses for charged and neutral pions are taken into account. (C) 2013 Elsevier B.V. All rights reserved.
Investigation of the dd -> 3henpi0 reaction with the FZ Jülich WASA-at-COSY facility
P. Adlarson, ..., W. Bardan, I. Ciepał, E. Czerwiński, M. Hodana, J. Klaja, W. Krzemień, I. Ozerianska, P. Moskal, M. Skurzok,M. Zieliński, et al.
abstract
An exclusive measurement of the dd?3Hen?0 reaction was carried out at a beam momentum of pd= 1.2 GeV/c using the WASA-at-COSY facility. Information on the total cross section as well as differential distributions was obtained. The data are described by a phenomenological approach based on a combination of a quasifree model and a partial wave expansion for the three-body reaction. The total cross section is found to be ?tot=(2.89?0.01stat?0.06sys?0.29norm) ?b. The contribution of the quasifree processes (with the beam or target neutron being a spectator) accounts for 38% of the total cross section and dominates the differential distributions in specific regions of phase space. The remaining part of the cross section can be described by a partial wave decomposition indicating the significance of p-wave contributions in the final state.
Search for a dark photon in the pi0->e+e-gamma decay
P. Adlarson, ..., M. Hodana, W. Krzemień, P. Moskal, I. Ozerianska, M. Skurzok, M. Zieliński et al.
abstract
The presently world largest data sample of pi0 --> gamma e+e- decays containing nearly 5E5 events was collected using the WASA detector at COSY. A search for a dark photon U produced in the pi0 --> gamma U --> gamma e+e- decay from the pp-->pppi^0 reaction was carried out. An upper limit on the square of the U-gamma mixing strength parameter epsilon^2 of 5e-6 at 90% CL was obtained for the mass range 30 MeV
TOF-PET detector concept based on organic scintillators
P. Moskal, T. Bednarski, P. Białas, M. Ciszewska, E. Czerwiński, A. Heczko, M. Kajetanowicz, Ł. Kapłon, A. Kochanowski, G. Konopka-Cupiał, G. Korcyl, W. Krzemień, K. Łojek, J. Majewski, W. Migdał, M. Molenda, S. Niedźwiecki, M. Pałka, Z. Rudy, P. Salabura, M. Silarski, A. Słomski, J. Smyrski, J. Zdebik, M. Zieliński
abstract
In this contribution we present a new concept of the large acceptance detector systems based on organic scintillators which may allow for simultaneous diagnostic of large fraction of the human body. Novelty of the concept lies in employing large blocks of polymer scintillators instead of crystals as detectors of annihilation quanta, and in using predominantly the timing of signals instead of their amplitudes.
Strip-PET: a novel detector concept for the TOF-PET scanner
P. Moskal, T. Bednarski, P. Białas, M. Ciszewska, E. Czerwiński, A. Heczko, M. Kajetanowicz, Ł. Kapłon, A. Kochanowski, G. Konopka-Cupiał, G. Korcyl, W. Krzemień, K. Łojek, J. Majewski, W. Migdał, M. Molenda, S. Niedźwiecki, M. Pałka, Z. Rudy, P. Salabura, M. Silarski, A. Słomski, J. Smyrski, J. Zdebik, M. Zieliński
abstract
We briefly present a design of a new PET scanner based on
strips of polymer scintillators arranged in a barrel constituting
a large acceptance detector. The solution proposed is based on
the superior timing properties of the polymer scintillators. The
position and time of the reaction of the gamma quanta in the
detector material will be determined based on the time of arrival
of light signals to the edges of the scintillator strips.
Measurement of eta meson production in gamma-gamma interactions and Gamma(eta-->gamma gamma) with the KLOE detector
D. Babusci, ..., I. Balwierz-Pytko, E. Czerwiński, P. Moskal, M. Silarski, W. Wiślicki, J. Zdebik et al.
abstract
We present a measurement of {eta} meson production in photon-photon interactions produced by electron-positron beams colliding with sqrt{s}=1 GeV. The measurement is done with the KLOE detector at the phi-factory DA{Phi}NE with an integrated luminosity of 0.24 fb^{-1}. The e^+e^- --> e^+e^-{eta} cross section is measured without detecting the outgoing electron and positron, selecting the decays {eta}-->{pi}^+{pi}^-{pi}^0 and {eta}-->{pi}^0{pi}^0{pi}^0. The most relevant background is due to e^+e^- --> {eta}{gamma} when the monochromatic photon escapes detection. The cross section for this process is measured as {sigma}(e^+e^- -->{eta}{gamma}) = (856 pm 8_{stat} pm 16_{syst}) pb. The combined result for the e^+e^- -->e^+e^-{eta} cross section is {sigma}(e^+e^- -->e^+e^-{eta}) = (32.72 pm 1.27_{stat} pm 0.70_{syst}) pb. From this we derive the partial width {Gamma}({eta}-->{gamma}{gamma}) = (520 pm 20_{stat} pm 13_{syst}) eV. This is in agreement with the world average and is the most precise measurement to date.
Search for the eta-mesic 4He with WASA-at-COSY detector
P. Adlarson, W. Augustyniak, W. Bardan, M. Bashkanov, T. Bednarski, FS. Bergmann, M. Berlowski, H. Bhatt, M. Buscher, H. Calen, H. Clement, D. Coderre, E. Czerwinski, K. Demmich, E. Doroshkevich, R. Engels, W. Erven, W. Eyrich, P. Fedorets, K. Fohl, K. Fransson, F. Goldenbaum, P. Goslawski, A. Goswami, K. Grigoryev, CO. Gullstrom, F. Hauenstein, L. Heijkenskjold, V. Hejny, F. Hinterberger, M. Hodana, B. Hoistad, A. Jany, BR. Jany, L. Jarczyk, T. Johansson, B. Kamys, G. Kemmerling, FA. Khan, A. Khoukaz, S. Kistryn, J. Klaja, H. Kleines, B. Klos, M. Krapp, W. Krzemien, P. Kulessa, A. Kupsc, K. Lalwani, D. Lersch, L. Li, B. Lorentz, A. Magiera, R. Maier, P. Marciniewski, B. Marianski, M. Mikirtychiants, HP. Morsch, P. Moskal, BK. Nandi, S. Niedzwiecki, H. Ohm, I. Ozerianska, EP. del Rio, P. Plucinski, P. Podkopal, et al.
abstract
An exclusive measurement of the excitation function for the dd->3Heppi- reaction was performed at the Cooler Synchrotron COSY-Juelich with the WASA-at-COSY detection system. The data were taken during a slow acceleration of the beam from 2.185 GeV/c to 2.400 GeV/c crossing the kinematic threshold for the eta meson production in the dd->4He-eta reaction at 2.336 GeV/c. The corresponding excess energy with respect to the 4He-eta system varied from -51.4MeV to 22MeV. The integrated luminosity in the experiment was determined using the dd->3Hen reaction. The shape of the excitation function for the dd->3Heppi- was examined. No signal of the 4He-eta bound state was observed. An upper limit for the cross-section for the bound state formation and decay in the process dd->(4He-eta)bound->3Heppi- was determined on the 90% confidence level and it varies from 20nb to 27nb for the bound state width ranging from 5MeV to 35MeV, respectively.
Limit on the production of a light vector gauge boson in phi meson decays with the KLOE detector
D. Babusci, ..., I. Balwierz-Pytko, E. Czerwiński, P. Moskal, M. Silarski, W. Wiślicki, J. Zdebik, et al
abstract
We present a new limit on the production of a light dark-force mediator with the KLOE detector at DAPHNE. This boson, called U, has been searched for in the decay phi -->eta U, with the hypothesis U-->e+e-, analyzing the decay eta-->pi0pi0pi0 in a data sample of 1.7 fb-1 integrated luminosity. This search is combined with a previous result obtained using the decay eta-->pi+pi-pi0, increasing substantially the sensitivity. No structures are observed in the e+e- invariant mass distribution over the background. Combining the two eta decay modes, we set an upper limit at 90% C.L. on the ratio between the U boson coupling constant and the fine structure constant of alpha'/alpha <= 1.5x10^-5 for 30
Precision measurement of sigma(e+e-->pi+pi-gamma)/sigma(e+e-->mu+mu-gamma) and determination of the pi+pi- contribution to the muon anomaly with the KLOE detector
D. Babusci, ..., P. Moskal, E. Czerwiński, I. Balwierz-Pytko, M. Silarski, W. Wiślicki, J. Zdebik et al.
abstract
We have measured the ratio $sigma(e^+e^-
ightarrowpi^+pi^-gamma)/sigma(e^+e^-
ightarrow mu^+mu^-gamma)$, with the KLOE detector at DA$Phi$NE for a total integrated luminosity of $sim$ 240 pb$^{-1}$. From this ratio we obtain the cross section $sigma(e^+e^-
ightarrowpi^+pi^-)$. From the cross section we determine the pion form factor $|F_pi|^2$ and the two-pion contribution to the muon anomaly $a_mu$ for $0.592
Measurement of Gamma(eta->pi^+pi^-gamma)/Gamma(eta->pi^+pi^-pi^0) with the KLOE Detector
D. Babusci, ..., I. Balwierz-Pytko, E. Czerwiński, M. Silarski, P. Moskal, J. Zdebik, et al.
abstract
Abashian-Booth-Crowe resonance structure in the double pionic fusion to He-4
P. Adlarson, W. Augustyniak, W. Bardan, M. Bashkanov, T. Bednarski, FS. Bergmann, M. Berlowski, H. Bhatt, KT. Brinkmann, M. Buscher, H. Calen, H. Clement, D. Coderre, E. Czerwinski, K. Demmich, E. Doroshkevich, R. Engels, W. Erven, W. Eyrich, P. Fedorets, K. Fohl, K. Fransson, F. Goldenbaum, P. Goslawski, K. Grigoryev, CO. Gullstrom, F. Hauenstein, L. Heijkenskjold, V. Hejny, F. Hinterberger, M. Hodana, B. Hoistad, C. Husmann, A. Jany, BR. Jany, L. Jarczyk, T. Johansson, B. Kamys, G. Kemmerling, FA. Khan, A. Khoukaz, S. Kistryn, J. Klaja, H. Kleines, B. Klos, W. Krzemien, P. Kulessa, A. Kupsc, K. Lalwani, D. Lersch, L. Li, B. Lorentz, A. Magiera, R. Maier, P. Marciniewski, B. Marianski, M. Mikirtychiants, HP. Morsch, P. Moskal, BK. Nandi, S. Niedzwiecki, H. Ohm, I. Ozerianska, C. Pauly, EP. del Rio, Y. Petukhov, et al.
abstract
Exclusive and kinematically complete high-statistics measurements of the double pionic fusion reaction dd?4He?0?0 have been performed in the energy range 0.8?1.4 GeV covering thus the region of the Abashian-Booth-Crowe effect, which denotes a pronounced low-mass enhancement in the ?? invariant mass spectrum. The experiments were carried out with the WASA detector setup at the cooler synchrotron at Forshungszentrum Julich GmbH. Similar to the observation in the basic pn?d?0?0 reaction, the data reveal a correlation between the ABC effect and a resonancelike energy dependence in the total cross section. The maximum occurs at m=2.37 GeV + 2mN, i.e., at the same position as in the basic reaction. The observed resonance width ??160 MeV can be understood from broadening due to Fermi motion of the nucleons in initial and final nuclei together with collision damping. Differential cross sections are described equally well by the hypothesis of a pn resonance formation during the reaction process.
Measurement of gamma(eta->pi+pi-gamma)/gamma(eta->pi+pi-pi0) with KLOE experiment
D. Babusci, ..., P. Moskal, ..., E. Czerwiński, ..., J. Balwierz, ..., M. Silarski, ..., J. Zdebik et al.
abstract
We report the measurement of the ratio $Gamma(eta o pi^+pi^-gamma)/Gamma(eta o pi^+pi^-pi^0)$ analyzing a large sample of $phi o eta gamma$ decays recorded with the KLOE experiment at the DA$Phi$NE $e^+ e^-$ collider, corresponding to an integrated luminosity of 558 pb$^{-1}$. The $eta o pi^+pi^-gamma$ process is supposed to proceed both via a resonant contribution, mediated by the $
ho$ meson, and a non resonant direct term, connected to the box anomaly. The presence of the direct term affects the partial width value. Our result $R_{eta}=Gamma(eta o pi^+ pi^- gamma)/Gamma(eta o pi^+ pi^- pi^0)= 0.1838pm 0.0005_{stat} pm 0.0030_{syst}$ is in agreement with a recent CLEO measurement, which differs by more 3 $sigma$ from the average of previous results.
Technical Design Report for the PANDA (AntiProton Annihilations at Darmstadt) Straw Tube Tracker
W. Erni, ..., S. Jowzaee, M. Kajetanowicz, B. Kamys, S. Kistryn, G. Korcyl, K. Korcyl, W. Krzemień, A. Magiera, P. Moskal, M. Palka, Z. Rudy, P. Salabura, J. Smyrski, A. Wrońska et al.
abstract
This document describes the technical layout and the expected performance of the Straw Tube Tracker (STT), the main tracking detector of the PANDA target spectrometer. The STT encloses a Micro-Vertex-Detector (MVD) for the inner tracking and is followed in beam direction by a set of GEM-stations. The tasks of the STT are the measurement of the particle momentum from the reconstructed trajectory and the measurement of the specific energy-loss for a particle identification. Dedicated simulations with full analysis studies of certain proton-antiproton reactions, identified as being benchmark tests for the whole Panda scientific program, have been performed to test the STT layout and performance. The results are presented, and the time lines to construct the STT are described.
Trapped Antihydrogen in Its Ground State
G. Gabrielse, R. Kalra, W. S. Kolthammer, R. McConnell, P. Richerme, D. Grzonka, W. Oelert, T. Sefzick, M. Zieliński, D. W. Fitzakerley, M. C. George, E. A. Hessels, C. H. Storry, M. Weel, A. Müllers, J. Walz
abstract
Antihydrogen atoms are confined in an Ioffe trap for 15 to 1000 seconds -- long enough to ensure that they reach their ground state. Though reproducibility challenges remain in making large numbers of cold antiprotons and positrons interact, 5 +/- 1 simultaneously-confined ground state atoms are produced and observed on average, substantially more than previously reported. Increases in the number of simultaneously trapped antithydrogen atoms are critical if laser-cooling of trapped antihydrogen is to be demonstrated, and spectroscopic studies at interesting levels of precision are to be carried out.
Physics topics at KLOE-2
M. Silarski on behalf of the KLOE-2 Collaboration
abstract
The goal of the KLOE?2 experiment operating at the upgraded DAFNE e+e? collider is to collect an integrated luminosity of about 20 fb?1 over 3-4 years of running. The KLOE?2 apparatus is now equipped with an inner tracker, new scintillation calorimeters and tagging detectors for gamma-gamma physics. These will allow measurements to refine and extend the KLOE programme on kaon physics and tests of fundamental symmetries as well as quantum interferometry. Here the latest results from the KLOE data analysis are presented and the perspectives at KLOE-2 outlined.
Exclusive measurement of the eta->pi+ pi- gamma decay
P. Adlarson, C. Adolph, W. Augustyniak, W. Bardan, M. Bashkanov, T. Bednarski, FS. Bergmann, M. Berlowski, H. Bhatt, KT. Brinkmann, M. Buscher, H. Calen, H. Clement, D. Coderre, E. Czerwinski, E. Doroshkevich, R. Engels, W. Erven, W. Eyrich, P. Fedorets, K. Fohl, K. Fransson, F. Goldenbaum, P. Goslawski, K. Grigoryev, CO. Gullstrom, C. Hanhart, L. Heijkenskjold, J. Heimlich, V. Hejny, F. Hinterberger, M. Hodana, B. Hoistad, M. Jacewicz, A. Jany, BR. Jany, L. Jarczyk, T. Johansson, B. Kamys, G. Kemmerling, O. Khakimova, A. Khoukaz, S. Kistryn, J. Klaja, H. Kleines, B. Klos, F. Kren, W. Krzemien, P. Kulessa, A. Kupsc, K. Lalwani, S. Leupold, B. Lorentz, A. Magiera, R. Maier, B. Marianski, P. Marciniewski, UG. Meissner, M. Mikirtychiants, HP. Morsch, P. Moskal, BK. Nandi, S. Niedzwiecki, H. Ohm, A. Passfeld, C. Pauly, et al.
abstract
An exclusive measurement of the decay eta --> pi+ pi- gamma has been performed at the WASA facility at COSY. The eta mesons were produced in the fusion reaction pd --> 3He X at a proton beam momentum of 1.7 GeV/c. Efficiency corrected differential distributions have been extracted based on 13340pm140 events after background subtraction. The measured pion angular distribution is consistent with a relative p-wave of the two-pion system, whereas the measured photon energy spectrum was found at variance with the simplest gauge invariant matrix element of eta --> pi+ pi- gamma. A parameterization of the data can be achieved by the additional inclusion of the empirical pion vector form factor multiplied by a first-order polynomial in the squared invariant mass of the pi+ pi- system.
On the possibility to measure the (pi0 to gamma gamma) decay width and the (gamma* gamma to pi0) transition form factor with the KLOE-2 experiment
D. Babusci, ..., and KLOE-2 Collaboration: F. Archilli, ..., I. Balwierz, E. Czerwiński, P. Moskal, M. Silarski, J. Zdebik et al.
abstract
A possibility of KLOE-2 experiment to measure the width Gamma(pi0 to gamma gamma) and the (pi0 gamma gamma*) form factor F(Q^2) at low invariant masses of the virtual photon in the space-like region is considered. This measurement is an important test of the strong interaction dynamics at low energies. The feasibility is estimated on the basis of a Monte-Carlo simulation. The expected accuracy for Gamma(pi0 to gamma gamma) is at a per cent level, which is better than the current experimental world average and theory. The form factor will be measured for the first time at Q^2 less or equal 0.1 GeV^2 in the space-like region. The impact of these measurements on the accuracy of the pion-exchange contribution to the hadronic light-by-light scattering part of the anomalous magnetic moment of the muon is also discussed.
Revealing Bells nonlocality for unstable systems in high energy physics
B. C. Hiesmayr, A. Di Domenico, C. Curceanu, A. Gabriel, M. Huber, J-A Larsson, P. Moskal
abstract
Entanglement and its consequences?in particular
the violation of Bell inequalities, which defies our concepts
of realism and locality?have been proven to play
key roles in Nature by many experiments for various quantum
systems. Entanglement can also be found in systems
not consisting of ordinary matter and light, i.e. in massive
meson?antimeson systems. Bell inequalities have been discussed
for these systems, but up to date no direct experimental
test to conclusively exclude local realism was found.
This mainly stems from the fact that one only has access to
a restricted class of observables and that these systems are
also decaying. In this Letter we put forward a Bell inequality
for unstable systems which can be tested at accelerator facilities
with current technology. Herewith, the long awaited
proof that such systems at different energy scales can reveal
the sophisticated dynamical nonlocal feature of Nature in
a direct experiment gets feasible. Moreover, the role of entanglement
and CP violation, an asymmetry between matter
and antimatter, is explored, a special feature offered only by
these meson?antimeson systems.
Search for the He-eta bound states with the WASA-at-COSY facility
M. Skurzok, P. Moskal, W. Krzemień
abstract
The existence of eta-mesic nuclei in which the eta meson is bound in a nucleus by means of the strong interaction was postulated already in 1986, albeit not yet confirmed it by experiment. The discovery of this new kind of an exotic nuclear matter would be very important as it might allow for a better understanding of the eta meson structure and its interaction with nucleons. The search for eta-mesic helium (4He-eta) is carried out with high statistics and high acceptance with the WASA detector, installed at the cooler synchrotron COSY of the Research Center Juelich. The search is conducted via the measurement of the excitation function for selected decay channels of the 4He-eta system. In the experiment, performed in November 2010, two reactions dd -> (4He-eta)bs -> 3He p pi- and dd -> (4He-eta)bs -> 3He n pi0 were measured with a beam momentum ramped from 2.127GeV/c to 2.422GeV/c. The report includes the description of the experimental method and status of the measurement.
Search for a vector gauge boson in phi meson decays with the KLOE detector
F. Ambrosino, ..., I. Balwierz, E. Czerwiński, P. Moskal, M. Silarski, J. Zdebik et al.
abstract
The existence of a light dark force mediator has been tested with the KLOE detector at DAFNE. This particle, called U, is searched for using the decay chain phi->eta U, eta->pi+pi-pi0, U->e+e-. No evidence is found in 1.5 fb-1 of data. The resulting exclusion plot covers the mass range 5
pi0 pi0 Production in proton-proton collisions at Tp=1.4 GeV
P. Adlarson, C. Adolph, W. Augustyniak, M. Bashkanov, T. Bednarski, FS. Bergmann, M. Berlowski, H. Bhatt, KT. Brinkmann, M. Buscher, H. Calen, H. Clement, D. Coderre, E. Czerwinski, E. Doroshkevich, R. Engels, W. Erven, W. Eyrich, P. Fedorets, K. Fohl, K. Fransson, F. Goldenbaum, P. Goslawski, K. Grigoryev, CO. Gullstrom, L. Heijkenskjold, J. Heimlich, V. Hejny, F. Hinterberger, M. Hodana, B. Hoistad, M. Jacewicz, M. Janusz, A. Jany, BR. Jany, L. Jarczyk, T. Johansson, B. Kamys, G. Kemmerling, O. Khakimova, A. Khoukaz, S. Kistryn, J. Klaja, H. Kleines, B. Klos, F. Kren, W. Krzemien, P. Kulessa, A. Kupsc, K. Lalwani, B. Lorentz, A. Magiera, R. Maier, B. Marianski, P. Marciniewski, M. Mikirtychiants, HP. Morsch, P. Moskal, BK. Nandi, S. Niedzwiecki, H. Ohm, A. Passfeld, C. Pauly, EP. del Rio, Y. Petukhov, N. Piskunov, et al.
abstract
The reaction pp->pppi0pi0 has been investigated at a beam energy of 1.4 GeV using the WASA-at-COSY facility. The total cross section is found to be (324 +- 21_systematic +- 58_normalization) mub. In order to to study the production mechanism, differential kinematical distributions have been evaluated. The differential distributions indicate that both initial state protons are excited into intermediate Delta(1232) resonances, each decaying into a proton and a single pion, thereby producing the pion pair in the final state. No significant contribution of the Roper resonance N*(1440) via its decay into a proton and two pions is found
Studies of the eta meson with WASA at COSY and KLOE-2 at DAFNE
P. Moskal
abstract
One of the basic motivations of the KLOE-2 and WASA-at-COSY experiments
is the test of fundamental symmetries and the search for phenomena beyond the
Standard Model in the hadronic and leptonic decays of ground-state mesons and in
particular in decays of the eta meson. At COSY these mesons are produced in collisions
of proton or deuteron beam with hydrogen or deuterium pellet target, and at
DAFNE eta mesons originate from radiative decays of fi meson or from the fusion of
virtual gamma quanta exchanged between colliding electrons and positrons. This
contribution includes brief description of experimental techniques used by KLOE-2
and WASA-at-COSY as well as some of physics aspects motivating investigations
of production and decays of ? mesons.
Novel detector systems for the Positron Emission Tomography
P. Moskal, P. Salabura, M. Silarski, J. Smyrski, J. Zdebik, M. Zieliński
abstract
In this contribution we describe a novel solution for the construction of Positron Emission Tomograph. We present
the device allowing for determination of the impact position as well as time and depth of interaction of the annihilation gamma
quanta. The device is comprised of scintillation chamber consisting of organic scintillators surrounding the body of the patient.
We discuss two possible solutions: (i) the tomograph built out of scintillator strips, and (ii) the tomograph built out of the scintillator
plates. The application of the fast scintillators will enable to take advantage of the difference between time of the registration of
the annihilation quanta. The invented method will permit to use a thick layers of detector material with the possibility of measuring
the depth of the gamma quantum interaction (DOI) and the determination of their time of fl ight (TOF), and will allow for increasing
the size of the diagnostic chamber without a signifi cant increase of costs. The method is a subject of two patent applications
[1, 2] which are based on the techniques used in the particle physics experiments [3, 4].
Observation of the rare eta->e+e-e+e- decay with the KLOE experiment
F. Ambrosino, ..., I. Balwierz, E. Czerwiński, P. Moskal, M. Silarski, J. Zdebik et al.
abstract
We report the first observation of the rare eta->e+e-e+e- decay based on 1.7 fb^{-1} collected by the KLOE experiment at the DAFNE phi-factory. The selection of the e+e-e+e- final state is fully inclusive of radiation. We have identified 362 +- 29 events resulting in a branching ratio of (2.4 +- 0.2_stat+bckg +- 0.1_syst) x 10^{-5}.
Reaction pp->pp pi pi pi as a background for hadronic decay of the eta-prime meson
M. Zieliński, P. Moskal, A. Kupść
abstract
Isospin violating hadronic decays of the eta and eta' mesons into 3pi mesons are driven by a term in the QCD Lagrangian proportional to the mass difference of the d and u quarks. The source giving large yield of the mesons for such decay studies are pp interactions close to the respective kinematical thresholds. The most important physics background for eta,eta' opipipi is coming from direct three pion production reactions. In case of the eta meson the background for the decays is relatively low (approx 10%). The purpose of this article is to provide an estimate of the direct pion production background for the eta' o 3pi decays. Using the inclusive data from COSY-11 experiment we have extracted differential cross section for the pp->pp-multipion production reactions with the invariant mass of the pions equal to the eta' meson mass and estimated an upper limit for the signal to background ratio for studies of the eta' opi^+pi^-pi^0 decay.
gamma gamma physics with the KLOE experiment
F. Archilli, ..., P. Moskal, E. Czerwiński, J. Zdebik, J. Balwierz, M. Silarski et al.
abstract
The processes $e^+e^- o e^+e^-X$, with $X$ being either the $eta$ meson or $pi^0pi^0$, are studied at DA$Phi$NE, with $e^+e^-$ beams colliding at $sqrt{s}simeq1$ GeV, below the $phi$ resonance peak. The data sample is from an integrated luminosity of 240 pb$^{-1}$, collected by the KLOE experiment without tagging of the outgoing $e^+e^-$. Preliminary results are presented on the observation of the $gammagamma oeta$ process, with both $eta opi^+pi^-pi^0$ and $eta opi^0pi^0pi^0$ channels, and the evidence for $gammagamma opi^0pi^0$ production at low $pi^0pi^0$ invariant mass.
Pumped helium system for cooling positron and electron traps to 1.2K
J. Wrubel, G. Gabrielse, W. S. Kolthammer, P. Larochelle, R. McConell, P. Richerme, D. Grzonka, W. Oelert, T. Sefzick, M. Zieliński, J. S. Borbely, M. C. George, E. A. Hassels, C. H. Storry, M. Weel, A. Muellers, J. Walz, A. Speck
abstract
Extremely precise tests of fundamental particle symmetries should be possible via laser spectroscopy of trapped antihydrogen () atoms. atoms that can be trapped must have an energy in temperature units that is below 0.5 K?the energy depth of the deepest magnetic traps that can currently be constructed with high currents and superconducting technology. The number of atoms in a Boltzmann distribution with energies lower than this trap depth depends sharply upon the temperature of the thermal distribution. For example, ten times more atoms with energies low enough to be trapped are in a thermal distribution at a temperature of 1.2 K than for a temperature of 4.2 K. To date, atoms have only been produced within traps whose electrode temperature is 4.2 K or higher. A lower temperature apparatus is desirable if usable numbers of atoms that can be trapped are to eventually be produced. This report is about the pumped helium apparatus that cooled the trap electrodes of an apparatus to 1.2 K for the first time. Significant apparatus challenges include the need to cool a 0.8 m stack of 37 trap electrodes separated by only a mm from the substantial mass of a 4.2 K Ioffe trap and the substantial mass of a 4.2 K solenoid. Access to the interior of the cold electrodes must be maintained for antiprotons, positrons, electrons and lasers.
Abashian-Booth-Crowe effect in basic double fusion: A new resonance?
P. Adlarson, C. Adolph, W. Augustyniak, V. Baru, M. Bashkanov, T. Bednarski, FS. Bergmann, M. Berlowski, H. Bhatt, KT. Brinkmann, M. Buscher, H. Calen, H. Clement, D. Coderre, E. Czerwinski, E. Doroshkevich, C. Ekstrom, R. Engels, W. Erven, W. Eyrich, P. Fedorets, K. Fohl, K. Fransson, F. Goldenbaum, P. Goslawski, K. Grigoryev, V. Grishina, CO. Gullstrom, J. Hampe, C. Hanhart, L. Heijkenskjold, V. Hejny, F. Hinterberger, M. Hodana, B. Hoistad, M. Jacewicz, M. Janusz, A. Jany, BR. Jany, L. Jarczyk, T. Johansson, B. Kamys, G. Kemmerling, O. Khakimova, A. Khoukaz, S. Kistryn, J. Klaja, H. Kleines, B. Klos, F. Kren, W. Krzemien, P. Kulessa, S. Kullander, A. Kupsc, K. Lalwani, B. Lorentz, A. Magiera, R. Maier, P. Marciniewski, B. Marianski, M. Mikirtychiants, P. Moskal, HP. Morsch, BK. Nandi, S. Niedzwiecki, H. Ohm, et al.
abstract
We report on an exclusive and kinematically complete high-statistics measurement of the basic double-pionic fusion reaction pn->dpi0pi0 over the full energy region of the ABC effect, a pronounced low-mass enhancement in the pipi-invariant mass spectrum. The measurements, which cover also the transition region to the conventional t-channel DeltaDelta process, were performed with the upgraded WASA detector setup at COSY. The data reveal the Abashian-Booth-Crowe effect to be uniquely correlated with a Lorentzian energy dependence in the integral cross section. The observables are consistent with a narrow resonance with m=2.37??GeV, Gamma aprox 70 MeV and I(JP)=0(3+) in both pn and DeltaDelta systems. Necessary further tests of the resonance interpretation are discussed.
Adiabatic Cooling of Antiprotons
G. Gabrielse, W. S. Kolthammer, R. McConell, P. Richerme, R. Kalra, E. Novitski, D. Grzonka, W. Oelert, T. Sefzick,M. Zieliński, D. Fitzakerley, M. C. George, E. A. Hassels, C. H. Storry, M. Weel, A. Müllers, J. Walz
abstract
Adiabatic cooling is shown to be a simple and effective method to cool many charged particles in a trap to very low temperatures. Up to 3×106 antiprotons are cooled to 3.5 K - 10^3 times more cold antiprotons and a 3 times lower antiproton temperature than previously reported. A second cooling method cools antiproton plasmas via the synchrotron radiation of embedded e- (with many fewer e- than antiproton ) in preparation for adiabatic cooling. No antiprotons are lost during either process - a significant advantage for rare particles.
Prospects for KLOE-2
P. Moskal for the collaboration KLOE-2
abstract
The basic motivation of the KLOE-2 experiment is the test of fundamental symmetries and Quantum Mechanics coherence of the neutral kaon system, and the search for phenomena beyond the Standard Model in the hadronic and leptonic decays of ground-state mesons. Perspectives for experimentation by means of the KLOE-2 apparatus equipped with the inner tracker, new scintillation calorimeters, and the gamma-gamma taggers at the DA$Phi$NE electron-positron collider upgraded in luminosity and energy are presented.
Measurement of the eta->pi+pi-pi0 decay with WASA-at-COSY detector
P. Adlarson, M. Zieliński
abstract
One of the objectives of the physics programme of the WASA-at-COSY facility is to study the isospin violating eta hadronic decays into pi+pi-pi0 systems driven by the term of QCD Lagrangian which depends on the d and u quark mass difference. These studies can be made in terms of the Dalitz plot parameters describing the density population which is proportional to the square of the amplitude |A(x, y)|2. This contribution describes the current status of the analysis of the eta->pi+pi-pi0 decay in the pd->3He-eta and as well in the pp->pp-eta reaction with WASA-at-COSY.
Study of the eta --> e+e-gamma decay with the WASA-at-COSY
M. Hodana
abstract
In October 2008, the WASA-at-COSY collected more than 107 events for the pd-->3He reaction. The aim is the determination of the invariant mass of the lepton pairs created in the Dalitz decay eta --> e+e-gamma. The e+e- invariant mass spectrum is directly related to the distribution of the four-momentum squared of the virtual photon from the eta-->gamma*gamma process and hence it allows for the study of the transition form factor which in turn reflects the structure of the decaying meson.
Study of the K+K- interaction at COSY-11
M. Silarski
abstract
In this article we present studies of the near threshold pp-->ppK+K? reaction in view of the K+K? final state interaction. The investigations include analysis of both the low-energy K+K? invariant mass distributions measured by COSY-11 collaboration at excess energies of Q = 10 MeV and Q = 28 MeV and the near threshold excitation function for the pp-->ppK+K? reaction. As a result of these studies we have estimated the K+K? scattering length more precise compared to the previous analysis based only on the analysis of the differential cross sections.
Centrifugal separation of antiprotons and electrons
G. Gabrielse, W. S. Kolthammer, R. McConell, P. Richerme, J. Wrubel, R. Kalra, E. Novitski, D. Grzonka, W. Oelert, T. Sefzick, M. Zieliński, J. S. Borbely, D. Fitzakerley, M. C. George, E. A. Hassels, C. H. Storry, M. Weel, A. Müllers, J. Walz, A. Speck
abstract
Centrifugal separation of antiprotons and electrons is observed, the first such demonstration with particles that cannot be laser cooled or optically imaged. The spatial separation takes place during the electron cooling of trapped antiprotons, the only method available to produce cryogenic antiprotons for precision tests of fundamental symmetries and for cold antihydrogen studies. The centrifugal separation suggests a new approach for isolating low energy antiprotons and for producing a controlled mixture of antiprotons and electrons.
Search for the eta-mesic nuclei by means of COSY-11, WASA-at-COSY and COSY-TOF detector systems
P. Moskal, J. Smyrski
abstract
We review status and perspectives of the search for the light eta-mesic nuclei using COSY-11, WASA-at-COSY and COSY-TOF detector systems.
Determination of the total width of the eta-prime meson
E. Czerwiński, P. Moskal, D. Grzonka, R. Czyżykiewicz, D. Gil, B. Kamys, A. Khoukaz, J. Klaja, P. Klaja, W. Krzemień, W. Oelert, J. Ritman, T. Sefzick, M. Siemaszko, M. Silarski, J. Smyrski, A. Täschner, M. Wolke, P. Wüstner, J. Zdebik, M. Zieliński, W. Zipper
abstract
Taking advantage of both the low-emittance proton beam of the cooler synchrotron COSY and the high momentum precision of the COSY-11 detector system, the mass distribution of the eta-prime meson was measured with a resolution of 0.33??MeV/c2 (FWHM), improving the experimental mass resolution by almost an order of magnitude with respect to previous results. Based on the sample of more than 2300 reconstructed pp->pp eta-prime events, the total width of the eta-prime meson was determined to be Gamma(eta-prime) = 0.226+-0.017(stat)+-0.014(syst)??MeV/c2.
Proton-proton correlation function for the pp->pp+ eta and pp->pp+pions reactions
P. Klaja, P. Moskal
abstract
For the very first time, the correlation femtoscopy method is applied to a kinematically complete measurement of meson production in the collisions of hadrons. The shape of the two-proton correlation function derived for the pp -> ppeta reaction differs from that for the pp -> pp(pions) and both do not show a peak structure opposite to results determined for inclusive measurements of heavy ion collisions.
Proposal for taking data with the KLOE-2 detector at the DAFNE collider upgraded in energy
D. Babusci, ..., P. Moskal, E. Czerwiński, I. Balwierz, M. Silarski, J. Zdebik, et al.
abstract
This document reviews the physics program of the KLOE-2 detector at DA$Phi$NE upgraded in energy and provides a simple solution to run the collider above the $phi$-peak (up to 2, possibly 2.5 GeV). It is shown how a precise measurement of the multihadronic cross section in the energy region up to 2 (possibly 2.5) GeV would have a major impact on the tests of the Standard Model through a precise determination of the anomalous magnetic moment of the muon and the effective fine-structure constant at the $M_Z$ scale. With a luminosity of about $10^{32}$cm$^{-2}$s$^{-1}$, DA$Phi$NE upgraded in energy can perform a scan in the region from 1 to 2.5 GeV in one year by collecting an integrated luminosity of 20 pb$^{-1}$ (corresponding to a few days of data taking) for single point, assuming an energy step of 25 MeV. A few years of data taking in this region would provide important tests of QCD and effective theories by $gammagamma$ physics with open thresholds for pseudo-scalar (like the $eta'$), scalar ($f_0,f'_0$, etc...) and axial-vector ($a_1$, etc...) mesons; vector-mesons spectroscopy and baryon form factors; tests of CVC and searches for exotics. In the final part of the document a technical solution for the energy upgrade of DA$Phi$NE is proposed.
Physics with the KLOE-2 experiment at the upgraded DAFNE
G. Amelino-Camelia, ..., E. Czerwiński, P. Moskal, M. Silarski, J. Zdebik et al.
abstract
Investigation at a $phi$--factory can shed light on several debated issues in particle physics. We discuss: i) recent theoretical development and experimental progress in kaon physics relevant for the Standard Model tests in the flavor sector, ii) the sensitivity we can reach in probing CPT and Quantum Mechanics from time evolution of entangled kaon states, iii) the interest for improving on the present measurements of non-leptonic and radiative decays of kaons and eta/eta$^prime$ mesons, iv) the contribution to understand the nature of light scalar mesons, and v) the opportunity to search for narrow di-lepton resonances suggested by recent models proposing a hidden dark-matter sector. We also report on the $e^+ e^-$ physics in the continuum with the measurements of (multi)hadronic cross sections and the study of gamma gamma processes.
Two-proton correlation function for the pp -> pp + eta and pp to pp + pions reactions
P. Klaja, P. Moskal, E. Czerwiński, R. Czyżykiewicz, A. Deloff, D. Gil, D. Grzonka, B. Kamys, A. Khoukaz, J. Klaja, W. Krzemień, W. Oelert, J. Ritman, T. Sefzick, M. Siemaszko, M. Silarski, J. Smyrski, A. Täschner, M. Wolke, J. Zdebik, M. Zieliński, W. Zipper
abstract
For the very first time, the correlation femtoscopy method is applied to a kinematically complete measurement of meson production in the collisions of hadrons. A two-proton correlation function was derived from the data for the pp -> ppX reaction, measured near the threshold of eta meson production. A technique developed for the purpose of this analysis permitted the correlation function to be established separately for the production of the pp + eta and of the pp + pions systems. The shape of the two-proton correlation function for pp-eta differs from that for pp(pions) and both do not show a peak structure, opposite to the results determined for inclusive measurements of heavy ion collisions.
Upper limit of the total cross section for the pn->pn eta-prime reaction
J. Klaja, P. Moskal, S. D. Bass, E. Czerwiński, R. Czyżykiewicz, D. Gil, D. Grzonka, T. Johansson, B. Kamys, A. Khoukaz, P. Klaja, W. Krzemień, W. Oelert, B. Rejdych, J. Ritman, T. Sefzick, M. Siemaszko, M. Silarski, J. Smyrski, A. Täschner, M. Wolke, P. Wüstner, J. Zdebik, M. Zieliński, W. Zipper
abstract
The upper limit of the total cross section for the pn->pneta-prime reaction has been determined near the kinematical threshold in the excess energy range from 0 to 24 MeV. The measurement was performed using the COSY-11 detector setup, a deuteron cluster target, and the proton beam of COSY with a momentum of 3.35 GeV/c. The energy dependence of the upper limit of the cross section was extracted exploiting the Fermi momenta of nucleons inside the deuteron. Comparison of the determined upper limit of the ratio R(eta-prime)=sigma(pn->pneta-prime)/sigma(pp->ppeta-prime) with the corresponding ratio for eta-meson production does not favor the dominance of the N*(1535) resonance in the production process of the eta-prime meson and suggests nonidentical production mechanisms for eta and eta-prime mesons.
Measurement of the invariant mass distributions fot he pp->pp eta-prime reaction at excess energy of Q = 16.4 MeV
P. Klaja, P. Moskal, E. Czerwiński, R. Czyżykiewicz, A. Deloff, D. Gil, D. Grzonka, L. Jarczyk, B. Kamys, A. Khoukaz, J. Klaja, K. Nakayama, W. Oelert, J. Ritman, T. Sefzick, M. Siemaszko, M. Silarski, J. Smyrski, A. Täschner, M. Wolke, J. Zdebik, M. Zieliński, W. Zipper
abstract
The proton?proton and proton? invariant mass distributions have been determined for the reaction at an excess energy of . The measurement was carried out using the COSY-11 detector setup and the proton beam of the cooler synchrotron COSY. The shapes of the determined invariant mass distributions are similar to those of the reaction and reveal an enhancement for large relative proton?proton momenta. This result, together with the fact that the proton?? interaction is much stronger that the proton? interaction, excludes the hypothesis that the observed enhancement is caused by the interaction between the proton and the meson.
Technical Design Report of the Inner Tracker for the KLOE-2 experiment
F. Archilli, ..., E. Czerwiński, J. Balwierz, P. Moskal, M. Silarski, J. Zdebik, et al.
abstract
The technical design report of the Inner Tracker for the KLOE-2 experiment is presented
Studies of properties of the eta' meson at the COSY-11 facility
E. Czerwiński, J. Klaja, P. Klaja, P. Moskal
abstract
We shortly discuss results on the isospin dependence of the eta-prime production cross section in nucleon-nucleon collisions, results of comparative analysis of the invariant mass distributions for the pp->pp eta-prime and pp->pp eta reactions, and we present the value of the total width of the eta-prime meson as derived directly from the mass distribution measured with the mass resolution of 0.3~MeV/c^2.
Invariant mass distributions for the pp->pp eta reaction at Q = 10 MeV
P. Moskal, R. Czyżykiewicz, E. Czerwiński, D. Gil, D. Grzonka, L. Jarczyk, B. Kamys, A. Khoukaz, J. Klaja, P. Klaja, W. Krzemień, W. Oelert, J. Ritman, T. Sefzick, M. Siemaszko, M. Silarski, J. Smyrski, A. Taschner, M. Wolke, P. Wustner, J. Zdebik, M. Zieliński, W. Zipper
abstract
Proton-proton and proton-eta invariant-mass distributions and the total cross-section for the pp -> pp h reaction have been determined near the threshold at an excess energy of Q = 10 MeV. The experiment has been conducted using the COSY-11 detector setup and the cooler synchrotron COSY. The determined invariant-mass spectra reveal significant enhancements in the region of low proton-proton relative momenta, similarly as observed previously at higher excess energies of Q = 15.5 MeV and Q = 40 MeV.
Generalized Dalitz plot analysis of the near-threshold pp->ppK+K- reaction in view of the K+K- final state interaction
M. Silarski, P. Moskal, E. Czerwiński, R. Czyżykiewicz, D. Gil, D. Grzonka, L. Jarczyk, B. Kamys, A. Khoukaz, J. Klaja, P. Klaja, W. Krzemień, W. Oelert, J. Ritman, T. Sefzick, M. Siemaszko, J. Smyrski, A. Täschner, P. Winter, M. Wolke, P. Wüstner, M. Zieliński, W. Zipper, J. Zdebik
abstract
The excitation function for the pp->ppK+K- reaction revealed a significant enhancement close to threshold which may plausibly be assigned to the influence of the pK- and K+K- final state interactions. In an improved reanalysis of COSY-11 data for the pp-> ppK+K- reaction at excess energies of Q = 10 MeV and 28 MeV including the proton-K- interaction the enhancement is confirmed. Invariant mass distributions for the two- and three-particle subsystems allow to test at low excess energies the ansatz and parameters for the description of the interaction in the ppK+K- system as derived from the COSY-ANKE data. Finally, based for the first time on the low energy K+K- invariant mass distributions and the generalized Dalitz plot analysis, we estimate the scattering length for the K+K- interaction to be |Re(a_K+K-)| = 0.5 + 4.0 -0.5 fm and Im(a_K+K-) = 3.0 +- 3.0 fm.
Technical Design Report for the PANDA Solenoid and Dipole Spectrometer Magnets
W. Erni, ..., P. Moskal et al.
abstract
This document is the Technical Design Report covering the two large spectrometer magnets of the PANDA detector set-up. It shows the conceptual design of the magnets and their anticipated performance. It precedes the tender and procurement of the magnets and, hence, is subject to possible modifications arising during this process.
Measurement of the eta->3pi0 Dalitz plot distribution with the WASA detector at COSY
WASA-at-COSY Collaboration: C. Adolph, ..., E. Czerwiński, R. Czyżykiewicz, M. Hodana, M. Janusz, J. Klaja, P. Klaja, W. Krzemień, P. Moskal, M. Zieliński, et al.
abstract
In the first production run of the WASA experiment at COSY, the eta decay into three neutral pions was measured in proton?proton interactions at a proton beam kinetic energy of 1.4 GeV. The Dalitz plot of the three pions was studied using fully reconstructed events, and the quadratic slope parameter ? was determined to be . The result is consistent with previous measurements and further corroborates the importance of pion?pion final state interactions.
Physics Performance Report for PANDA: Strong Interaction Studies with Antiprotons
W. Erni, ... , W.Krzemień et al.
abstract
To study fundamental questions of hadron and nuclear physics in interactions of antiprotons with nucleons and nuclei, the universal PANDA detector will be built. Gluonic excitations, the physics of strange and charm quarks and nucleon structure studies will be performed with unprecedented accuracy thereby allowing high-precision tests of the strong interaction. The proposed PANDA detector is a state-of-the art internal target detector at the HESR at FAIR allowing the detection and identification of neutral and charged particles generated within the relevant angular and energy range. This report presents a summary of the physics accessible at PANDA and what performance can be expected.
Near-threshold production of the eta meson via the quasi-free pn->pneta reaction
P. Moskal, R. Czyżykiewicz, H.-H. Adam, S. D. Bass, A. Budzanowski, E. Czerwiński, D. Gil, D. Grzonka, M. Janusz, L. Jarczyk, T. Johansson, B. Kamys, A. Khoukaz, K. Kilian, P. Klaja, J. Majewski, W. Oelert, C. Piskor-Ignatowicz, J. Przerwa, B. Rejdych, J. Ritman, T. Rozek, T. Sefzick, M. Siemaszko, M. Silarski, J. Smyrski, A. Taeschner, M. Wolke, P. Wuestner, M. Zieliński, W. Zipper, J. Zdebik
abstract
Total cross sections for the quasifree pn->pn? reaction in the range from the kinematical threshold up to 20 MeV excess energy have been determined. At threshold they exceed corresponding cross sections for the pp?pp? reaction by a factor of about 3 in contrast to the factor of 6 established for higher excess energies. To large extent, the observed decrease of the ratio sigma(pn->pn?)/sigma(pp->pp?) toward threshold may be assigned to the different energy dependence of the proton-proton and proton-neutron final-state interactions. The experiment was conducted using a proton beam of the cooler synchrotron COSY and a cluster jet deuteron target. The proton-neutron reactions were tagged by the spectator proton whose momentum was measured for each event. Protons and neutron outgoing from the pn?pn? reaction have been registered by means of the COSY-11 facility, an apparatus dedicated for threshold meson production.
Search for the eta-mesic helium at COSY
P. Moskal
abstract
We review status and perspectives of the search of the eta-mesic helium at the cooler synchrotron COSY.
Isospin dependence of the eta-prime meson production in nucleon-nucleon collisions
J. Przerwa, P. Moskal, A. Budzanowski, E. Czerwiński, R. Czyżykiewicz, D. Gil, D. Grzonka, L. Jarczyk, T. Johansson, B. Kamys, A. Khoukaz, P. Klaja, W. Krzemień, W. Oelert, C. Piskor-Ignatowicz, J. Ritman, B. Rejdych, T. Sefzick, M. Siemaszko, M. Silarski, J. Smyrski, A. Taschner, M. Wolke, P. Wustner, J. Zdebik, M. Zieliński, W. Zipper
abstract
A comparison of the close-to-threshold total cross section for the eta prime production in pp -> pp eta prime and pn -> pn eta prime reactions constitutes a tool to investigate the eta prime meson structure and the reaction mechanism in the channels of isospin I=0 and I=1 and may provide insight into the flavour-singlet (perhaps also into gluonium) content of the eta prime meson. In this contribution we present preliminary results of measurement of the quasi-free production of the eta prime meson in the proton-neutron collisions conducted using the COSY-11 facility.
Search for the 3He-eta bound state at COSY-11
W. Krzemien, J. Smyrski, A. Budzanowski, E. Czerwiński, R. Czyżykiewicz, D. Gil, D. Grzonka, L. Jarczyk, B. Kamys, A. Khoukaz, P. Klaja, P. Moskal, W. Oelert, J. Przerwa, J. Ritman, T. Sefzick, M. Siemaszko, M. Silarski, A. Taeschner, M. Wolke, P. Wuestner, J. Zdebik, M. Zieliński, W. Zipper
abstract
We have measured excitation function for dp -> ppp_pi- reaction near the eta production threshold. We observe an enhancement of the counting rate above the threshold which can originate from the production of the eta meson in the reaction dp -> 3He eta and its subsequent absorption on neutron in the 3He nucleus leading to creation of the p_pi- pair.
Eta and eta-prime mesons production at COSY-11
P. Moskal, H.-H. Adam, A. Budzanowski, E. Czerwinski, R. Czyzykiewicz, D. Gil, D. Grzonka, M. Janusz, L. Jarczyk, B. Kamys, A. Khoukaz, P. Klaja, J. Majewski, W. Oelert, C. Piskor-Ignatowicz, J. Przerwa, J. Ritman, B. Rejdych, T. Rozek, T. Sefzick, M. Siemaszko, J. Smyrski, A. Taeschner, P. Winter, M. Wolke, P. Wuestner, W. Zipper
abstract
The low emittance and small momentum spread of the proton and deuteron beams of the Cooler Synchrotron COSY combined with the high mass resolution of the COSY-11 detection system permit to study the creation of mesons in the nucleon-nucleon interaction down to the fraction of MeV with respect to the kinematical threshold. At such small excess energies, the ejectiles possess low relative momenta and are predominantly produced with the relative angular momentum equal to zero. Taking advantage of these conditions we have performed investigations aiming to determine the mechanism of the production of eta and eta' mesons in the collision of hadrons as well as the hadronic interaction of these mesons with nucleons and nuclei. In this proceedings we address the ongoing studies of the spin and isospin dependence for the production of the eta and eta' mesons in free and quasi-free nucleon-nucleon collisions. New results on the spin observables for the vec(p)p --> pp eta reaction, combined with the previously determined total cross section isospin dependence, reveal a statistically significant indication that the excitation of the nucleon to the S11(1535) resonance, the process which intermediates the production of the eta meson in the nucleon-nucleon interactions, is predominantly due to the exchange of the pi meson between the colliding nucleons.
General thoughts to the Kaon pair production in the threshold region
W. Oelert, H.-H. Adam, A. Budzanowski, E. Czerwinski, R. Czyzykiewicz, D. Gil, D. Grzonka, M. Janusz, L. Jarczyk, B. Kamys, A. Khoukaz, P. Klaja, P. Moskal, C. Piskor-Ignatowicz, J. Przerwa, T. Rozek, R. Santo, T. Sefzick, M. Siemaszko, J. Smyrski, A. Taschner, P. Winter, M. Wolke, P. Wustner, W. Zipper
abstract
Simple--minded thoughts about the cross sections for the reactions pp-->ppK+K- and pp-->ppK0K0 are presented, which certainly do not account for the complex coupled channel problem but rather provide some ideas into the mutual reaction dynamics.
Study of the production mechanism of the eta meson by means of analysing power measurements
R. Czyżykiewicz, P. Moskal, H.-H. Adam, A. Budzanowski, E. Czerwiński, D. Gil, D. Grzonka, M. Janusz, L. Jarczyk, B. Kamys, A. Khoukaz, P. Klaja, B. Lorentz, J. Majewski, W. Oelert, C. Piskor-Ignatowicz, J. Przerwa, J. Ritman, H. Rohdjess, T. Rozek, T. Sefzick, M. Siemaszko, J. Smyrski, A. Taeschner, K. Ulbrich, P. Winter, M. Wolke, P. Wuestner, W. Zipper
abstract
Information about the production mechanism of the eta meson in proton-proton collisions can be inferred by confronting the experimental studies on the analysing power for the p(pol)p --> pp eta reaction with the theoretical predictions of this observable. Results show that the predictions of pure pseudoscalar- or vector meson exchange model are insufficient to describe the analysing powers.
Near threshold eta meson production in dp collisions
C. Piskor-Ignatowicz, J. Smyrski, P. Moskal, H.-H. Adam, A. Budzanowski, E. Czerwiński, R. Czyżykiewicz, D. Gil, D. Grzonka, M. Janusz, L. Jarczyk, B. Kamys, A. Khoukaz, P. Klaja, J. Majewski, W. Oelert, J. Przerwa, J. Ritman, T. Rozek, T. Sefzick, M. Siemaszko, A. Taeschner, P. Winter, M. Wolke, P. Wuestner, W. Zipper
abstract
Preliminary results of recent measurements of the near threshold eta meson production in the dp-->dp eta reaction are presented. The experiment was performed at the COSY-Juelich accelerator with the use of the COSY-11 detection system. Data were taken for three values of deuteron beam momenta corresponding to excess energies of 3.2, 6.1 and 9.2 MeV. The energy dependence of the total cross section confirms a strong effect of the final state interaction.
Study of the low energy interaction of hadrons at COSY-11
P. Moskal, R. Czyżykiewicz, E. Czerwiński, D. Grzonka, A. Budzanowski, D. Gil, M. Janusz, L. Jarczyk, B. Kamys, A. Khoukaz, P. Klaja, W. Oelert, C. Piskor-Ignatowicz, J. Przerwa, B. Rejdych, J. Ritman, T. Sefzick, M. Siemaszko, M. Silarski, J. Smyrski, A. Täschner, M. Wolke, P. Wüstner, M. Zieliński, W. Zipper
abstract
We summarize the studies of the low energy hadronic interaction of the KK and pK system performed by the COSY-11 collaboration. We discuss also the question of the existence of the ??3He bound state in the context of the experiments conducted by means of the COSY-11 facility
Measurement of the dp -> He-3 eta reaction near threshold
J. Smyrski, H.-H. Adam, A. Budzanowski, E. Czerwiński, R. Czyżykiewicz, D. Gil, D. Grzonka, M. Janusz, L. Jarczyk, B. Kamys, A. Khoukaz, P. Klaja, T. Mersmann, P. Moskal, W. Oelert, C. Piskor-Ignatowicz, J. Przerwa, B. Rejdych, J. Ritman, T. Rozek, T. Sefzick, M. Siemaszko, A. Taeschner, P. Winter, M. Wolke, P. Wuestner, W. Zipper
abstract
Total and differential cross sections for the dp --> 3He eta reaction have been measured near threshold for 3He center-of-mass momenta in the range from 17.1 MeV/c to 87.5 MeV/c. The data were taken during a slow ramping of the COSY internal deuteron beam scattered on a proton target detecting the 3He ejectiles with the COSY-11 facility. The forward-backward asymmetries of the differential cross sections deviate clearly from zero for center-of-mass momenta above 50 MeV/c indicating the presence of higher partial waves in the final state. Below 50 MeV/c center-of-mass momenta a fit of the final state enhancement factor to the data of the total cross sections results in the 3He eta scattering length of a = |2.9 +/- 0.6| + i (3.2 +/- 0.4) fm.
Direct measurement of the total width of the eta prime meson
E. Czerwiński, P. Moskal, D. Grzonka, A. Budzanowski, R. Czyżykiewiczy, D. Gil, M. Janusz, L. Jarczyk, B. Kamys, A. Khoukaz, P. Klaja, W. Oelert, C. Piskor-Ignatowicz, J. Przerwa, B. Rejdych, J. Ritman, T. Sefzick, M. Siemaszko, M. Silarski, J. Smyrski, A. Täschner, M. Wolke, P. Wüstner, M. Zieliński, W. Zipper
abstract
Using stochastically cooled proton beam of the cooler synchrotron COSY and the COSY-11 apparatus we have measured the mass distribution of the eta prime meson producing it via the pp->ppeta' reaction. The preliminary analysis shows that the achieved experimental mass resolution amounts to about 0.3 MeV (FWHM). Such precision with about 2300 events gathered at five excess energies should permit for the extraction of the width of the eta' meson with an accuracy of about 10 keV. In this article we describe the method of the mea-surement and present preliminary results.
Hadronic He-3 eta production near threshold
H.-H. Adam, I. Geck, A. Khoukaz, T. Lister, R. Santo, S. Steltenkamp, A. Täschner, E. Czerwiński, R. Czyżykiewicz, M. Janusz, L. Jarczyk, B. Kamys, P. Klaja, P. Moskal, C. Piskor-Ignatowicz, J. Przerwa, J. Smyrski, D. Grzonka, K. Kilian, W. Oelert, T. Sefzick, P. Winter, M. Wolke, P. Wüstner, A. Budzanowski, T. Rożek, M. Siemaszko, W. Zipper
abstract
Measurements of ? meson production in proton-deuteron collisions have been performed using the COSY-11 facility at COSY (Jülich). Results on total and differential cross sections for the pd?3He? reaction are presented at five excess energies between Q=5.0 and Q=40.6 MeV. The angular distributions show a transition from an almost isotropic emission close to threshold to a highly anisotropic distribution at higher excess energies. The total cross sections reveal a strong ?-3He final state interaction, corresponding to a scattering length of |?(a)|=(4.2?0.5) fm and ?(a)=(0.4?1.9) fm
Study of the He-3 eta system in d p collisions
J. Smyrski, H.-H. Adam, A.Budzanowski, E. Czerwiński, R. Czyżykiewicz, D. Gil, D. Grzonka, M. Janusz, L. Jarczyk, B. Kamys, A. Khoukaz, P. Klaja, P. Moskal, W. Oelert, C. Piskor-Ignatowicz, J. Przerwa, J. Ritman, T. Rozek, T. Sefzick, M. Siemaszko, A. Taeschner, P. Winter, M. Wolke, P. Wuestner, W. Zipper
abstract
We have measured excitation functions for the d+p->3He+X, (X=pi0, eta) channels near the eta production threshold. The data were taken during a slow ramping of the COSY internal deuteron beam scattered on a proton target. The excitation function for the reaction d+p->3He+pi0 does not show any structure which could originate from the decay of 3He-eta bound state. We measured also the threshold excitation curve for the d+p->3He+X process, however, contrary to the SATURNE results, we observe no cusp near the eta threshold.
Mechanism of the close-to-threshold production of the eta meson
R. Czyzykiewicz, P. Moskal, H. -H. Adam, A. Budzanowski, E. Czerwinski, D. Gil, D. Grzonka, M. Hodana, M. Janusz, L. Jarczyk, B. Kamys, A. Khoukaz, K. Kilian, P. Klaja, B. Lorentz, W. Oelert, C. Piskor-Ignatowicz, J. Przerwa, B. Rejdych, J. Ritman, T. Sefzick, M. Siemaszko, J. Smyrski, A. Taeschner, K. Ulbrich, P. Winter, M. Wolke, P. Wuestner, W. Zipper
abstract
Measurements of the analysing power for the p(pol)p --> ppeta reaction have been performed in the close-to-threshold energy region at beam momenta of p_{beam}=2.010 and 2.085 GeV/c, corresponding to excess energies of Q=10 and 36 MeV, respectively. The determined analysing power is essentially consistent with zero implying that the eta meson is produced predominantly in the s-wave at both excess energies. The angular dependence of the analysing power, combined with the hitherto determined isospin dependence of the total cross section for the eta meson production in nucleon-nucleon collisions, reveal a statistically significant indication that the excitation of the nucleon to the S_{11}(1535) resonance, the process which intermediates the production of the eta meson, is predominantly due to the exchange of the pi meson between the colliding nucleons.
The Analysing power for the polarized-p p ---> p p eta reaction at Q=10MeV
R. Czyzykiewicz, P. Moskal, H.-H. Adam, A. Budzanowski, E. Czerwinski, D. Gil, D. Grzonka, M. Janusz, L. Jarczyk, B. Kamys, A. Khoukaz, K. Kilian, P. Klaja, B. Lorentz, J. Majewski, W. Oelert, C. Piskor-Ignatowicz, J. Przerwa, J. Ritman, H. Rohdjess, T. Rozek, R. Santo, T. Sefzick, M. Siemaszko, J. Smyrski, A. Taeschner, K. Ulbrich, P. Winter, M. Wolke, P. Wuestner, Z. Zhang, W. Zipper
abstract
The analyzing power A_y for the p(pol)p --> pp eta reaction has been determined at the beam momentum p_{beam}=2010 MeV/c, corresponding to the excess energy Q=10 MeV. In the paper the method of the data analysis is briefly presented.
Study of the He-3 - eta system in d-p collisions at COSY-11
J. Smyrski, H.-H. Adam, A. Budzanowski, E. Czerwinski, R. Czyzykiewicz, D. Gil, D. Grzonka, A. Heczko, M. Janusz, L. Jarczyk, B. Kamys, A. Khoukaz, K. Kilian, P. Klaja, J. Majewski, P. Moskal, W. Oelert, C. Piskor-Ignatowicz, J. Przerwa, J. Ritman, T. Rozek, R. Santo, T. Sefzick, M. Siemaszko, A. Taeschner, P. Winter, M. Wolke, P. Wuestner, Z. Zhang, W. Zipper
abstract
We present preliminary results from dp --> 3He X (X=pi0,eta) measurements near the eta production threshold. The data were taken during a slow ramping of the COSY internal deuteron beam scattered on a proton target. The 3He ejectiles were registered with the COSY-11 detection setup. The ongoing data analysis should deliver high precision data for the dp --> 3He eta total and differential cross sections for the excess energies in the range from threshold up to 9 MeV. The preliminary excitation function for the reaction dp --> 3He pi0 does not show any structure which could originate from the decay of 3He-eta bound state. We present also a threshold excitation curve for the dp --> 3He X channel. Contrary to corresponding results from SATURNE we see no cusp in the vicinity of the eta threshold.
Correlation femtoscopy for studying eta meson production mechanism
P. Klaja, P. Moskal, H.-H. Adam, A. Budzanowski, E. Czerwinski, R. Czyzykiewicz, D. Gil, D. Grzonka, M. Janusz, L. Jarczyk, B. Kamys, A. Khoukaz, K. Kilian, J. Majewski, W. Migdal, W. Oelert, C. Piskor-Ignatowicz, J. Przerwa, J. Ritman, T. Rozek, R. Santo, T. Sefzick, M. Siemaszko, J. Smyrski, A. Taeschner, P. Winter, M. Wolke, P. Wuestner, Z. Zhang, W. Zipper
abstract
The high statistics data from the pp -> ppeta reaction measurement, delivered by the COSY-11 collaboration, are now being evaluated using the correlation femtoscopy technique. This method is based on the relative momentum correlations of two emitted protons and may permit determination of the size of the reaction volume. For the very first time, we apply an intensity interferometry technique to study the mechanism of the meson production via the nucleon-nucleon interaction close to the kinematical threshold. We invented a method to determine correlation function for the ppeta system free from the physical multi-pion production background. We show the comparison of experimental results with theoretical predictions and appraise the accuracy achieved for the determination of the size of the emission source.
Threshold hyperon production in proton-proton collisions at COSY-11
T. Rozek, D. Grzonka, H.-H. Adam, A. Budzanowski, R. Czyzykiewicz, M. Janusz, L. Jarczyk, B. Kamys, A. Khoukaz, K. Kilian, P. Klaja, P. Kowina, P. Moskal, W. Oelert, C. Piskor-Ignatowicz, J. Przerwa, J. Ritman, T. Sefzick, M. Siemaszko, J. Smyrski, A. Taschner, P. Winter, M. Wolke, P. Wustner, Z. Zhang, W. Zipper
abstract
Sigma+ hyperon production was measured at the COSY-11 spectrometer via the p p --> n K+ Sigma+ reaction at excess energies of Q = 13 MeV and Q = 60 MeV. These measurements continue systematic hyperon production studies via the p p --> p K+ Lambda/Sigma0 reactions where a strong decrease of the cross section ratio close-to-threshold was observed. In order to verify models developed for the description of the Lambda and Sigma0 production we have performed the measurement on the Sigma+ hyperon and found unexpectedly that the total cross section is by more than one order of magnitude larger than predicted by all anticipated models.
After the reconstruction of the kaon and neutron four momenta, the Sigma+ is identified via the missing mass technique. Details of the method and the measurement will be given and discussed in view of theoretical models.
Kaon pair production close to threshold
P. Winter, M. Wolke, H.-H. Adam, A. Budzanowski, R. Czyzykiewicz, D. Grzonka, M. Janusz, L. Jarczyk, B. Kamys, A. Khoukaz, K. Kilian, P. Klaja, P. Moskal, W. Oelert, C. Piskor-Ignatowicz, J. Przerwa, J. Ritman, T. Rozek, T. Sefzick, M. Siemaszko, J. Smyrski, A. Taschner, P. Wustner, Z. Zhang, W. Zipper
abstract
The total cross section of the reaction pp->ppK+K- has been measured at excess energies Q=10 MeV and 28 MeV with the magnetic spectrometer COSY-11. The new data show a significant enhancement of the total cross section compared to pure phase space expectations or calculations within a one boson exchange model. In addition, we present invariant mass spectra of two particle subsystems. While the K+K- system is rather constant for different invariant masses, there is an enhancement in the pK- system towards lower masses which could at least be partially connected to the influence of the Lambda(1405) resonance.
A method to disentangle single- and multi-meson production in missing mass spectra from quasi-free pn ---> pn X reactions
P. Moskal, H.-H. Adam, A. Budzanowski, R. Czyzykiewicz, D. Grzonka, M. Janusz, L. Jarczyk, T. Johansson, B. Kamys, P. Klaja, A. Khoukaz, K. Kilian, J. Majewski, W. Oelert, C. Piskor-Ignatowicz, J. Przerwa, J. Ritman, T. Rozek, T. Sefzick, M. Siemaszko, J. Smyrski, A. Taeschner, J. Wessels, P. Winter, M. Wolke, P. Wuestner, Z. Zhang, W. Zipper
abstract
The separation of contributions from multi- and single-meson production in the missing mass spectrum of the quasi-free pn --> pnX reaction constitutes a~challenging task when the reaction is studied close to threshold. This is especially true if the resolution of the mass determination is comparable with the excess energy and if the investigated signal appears close to the kinematical limit. In this article we outline a method which permits the extraction of the signal originating from the creation of a single meson without the necessity of conducting model-dependent simulations. For the pd --> pnXp(spectator) reactions, the method allows one to combine events corresponding to multi-meson production at various excess energies with respect to the pn --> pn meson process, and hence leads to an increase of the statistics needed for the determination of the shape of the multi-meson background.
As an example of the application of the method, we demonstrate that the evaluation of the data from the pd --> pnXp(sp) process according to the described technique enables one to extract a signal of the pn --> pn eta reaction whose shape is consistent with expectations, supporting the correctness and usefulness of the method introduced.
Drift chamber with a c-shaped frame
J. Smyrski, Ch. Kolf, H.-H. Adam, A. Budzanowski, R. Czyzykiewicz, D. Grzonka, A. Heczko, M. Janusz, L. Jarczyk, B. Kamys, A. Khoukaz, K. Kilian, P. Kowina, A. Misiak, P. Moskal, W. Oelert, C. Piskor-Ignatowicz, J. Przerwa, C. Quentmeier, T. Rozek, R. Santo, G. Schepers, T. Sefzick, M. Siemaszko, A. Taschner, P. Winter, M. Wolke, P. Wustner, W. Zipper
abstract
We present the construction of a planar drift chamber with wires stretched between two arms of a c-shaped aluminium frame. The special shape of the frame allows to extendthe momentum acceptance of the COSY-11 detection system towards lower momenta without suppressing the high momentum particles. The proposed design allows for construction of tracking detectors covering small angles with respect to the beam, which can be installed and removed without dismounting the beam-pipe. For a three-dimensional track reconstruction a computer code was developed using a simple algorithm of hit preselection.
Energy dependence of the Lambda / Sigma0 production cross-section ratio in p-p interactions.
P. Kowina, ..., P. Moskal et al.
abstract
The production of the Lambda and Sigma0 hyperons has been measured via the pp->pK+Lambda / Sigma0 reaction at the internal COSY-11 facility in the excess energy range between 14 and 60 MeV. The transition of the Lambda/Sigma0 cross section ratio from about 28 at Q<=13 MeV to the high energy level of about 2.5 is covered by the data showing a strong decrease of the ratio between 10 and 20 MeV excess energy.
Effects from the final state interactions in the p-Sigma0 channel seem to be much smaller compared to the p-Lambda one. Estimates of the effective range parameters are given for the N-Lambda and the N-Sigma systems.
Total and differential cross-sections for the pp -> pp eta prime reaction near threshold
A. Khoukaz, ..., A. Budzanowski, R. Czyżykiewicz, P. Moskal et al.
abstract
The eta-prime meson production in the reaction pp-->pp eta-prime has been studied at excess energies of Q = 26.5, 32.5 and 46.6 MeV using the internal beam facility COSY-11 at the cooler synchrotron COSY. The total cross sections as well as one angular distribution for the highest Q-value are presented. The excitation function of the near threshold data can be described by a pure s-wave phase space distribution with the inclusion of the proton-proton final state interaction and Coulomb effects. The obtained angular distribution of the eta-prime mesons is also consistent with pure s-wave production.
Experimental study of pp eta dynamics in the pp -> pp eta reaction
P. Moskal, ..., H.-H. Adam, A. Budzanowski, R. Czyzykiewicz, D. Grzonka, M. Janusz, L. Jarczyk, B. Kamys, M. Siemaszko, J. Smyrski et al.
abstract
A high statistics measurement of the pp --> ppeta reaction at an excess energy of Q = 15.5 MeV has been performed at the internal beam facility COSY-11. The stochastically cooled proton beam and the used detection system allowed to determine the momenta of the outgoing protons with a precision of 4 MeV/c (sigma) in the center-of-mass frame. The determination of the four-momentum vectors of both outgoing protons allowed to derive the complete kinematical information of the ppeta-system.
An unexpectedly large enhancement of the occupation density in the kinematical regions of low proton-eta relative momenta is observed. A description taking the proton-proton and the eta-proton interaction into account and assuming an on-shell incoherent pairwise interaction among the produced particles fails to explain this strong effect. Its understanding will require a rigorous three-body approach to the ppeta system and the precise determination of contributions from higher partial waves.
We also present an invariant mass spectrum of the proton-proton system determined at Q = 4.5 MeV. Interestingly, the enhancement at large relative momenta between protons is visible also at such a small excess energy.
In contrast to all other determined angular distributions, the orientation of the emission plane with respect to the beam direction is extracted to be anisotropic.
Eta physics at threshold
P. Moskal, ..., A. Budzanowski, D. Grzonka, M. Janusz, K. Kilian et al.
abstract
The production of eta and eta-prime mesons in elementary nucleon-nucleon collisions has been investigated at the synchrotrons CELSIUS, COSY and SATURNE. The magnitude and energy dependence of the total cross section as well as the occupation distribution of the phase space serve as observables for investigating the mechanisms underlying the production processes and the interaction of mesons with nucleons. The precise data on the eta and eta-prime creation via the pp --> pp eta(eta-prime) reactions allowed to settle the general features of the eta and eta-prime meson production and revealed the sensitivity of the mentioned observables to the nucleon-nucleon-meson final state interaction. The particular production properties, like for example the determination of the dominating exchange processes which lead to the excitation of the S_11 nucleon isobar in the case of eta creation, must be established by confrontation with other observables. The present status of this investigation with an emphasis on the results of the COSY-11 collaboration is briefly presented. The available data are interpreted in view of the production mechanism and the meson-nucleon interaction.
Upper limit for the cross-section of the overlapping scalar resonances f(0)(980) and a(0)(980) produced in proton proton collisions in the range of the reaction threshold
P. Moskal, ..., H. H. Adam, A. Budzanowski, R. Czyżykiewicz, D. Grzonka, K. Kilian et al.
abstract
Utilizing a missing mass technique we investigate the pp ? ppX reaction scanning beam energies in the range permitting to create a mass close to that of the f0(980) and a0(980) scalar resonances, but still below the K+K? threshold where they decay dominantly into ?? and ?? mesons, respectively. Prior to the data analysis we introduce a notion of the close to threshold total cross-section for broad resonances. We estimated for the overlapping mesons a0 and f0 the total cross-section to be smaller than 430 nb at excess energy of Q = 5 MeV. The experiment has been performed at the Cooler Synchrotron (COSY) using the COSY-11 facility.
Study of the eta proton interaction via the reaction p p -> p p eta
P. Moskal, ..., H.H. Adam, A. Budzanowski, R. Czyzykiewicz, T. Gotz, D. Grzonka, M. Siemaszko, J. Smyrski, S. Steltenkamp, A. Strzalkowski, et al.
abstract
PiN Newslett. 16 (2002) 367-369
A measurement of the pp --> p p eta reaction at the excess energy of Q = 15.5 +- 0.4 MeV has been carried out at the internal beam facility COSY-11 with an integrated luminosity of 811 nb^-1 The number of ~24000 identified events permits a precise determination of total (2.32 +- 0.05 +- 0.35 mu b) and differential cross sections. Preliminary investigations show that the angular distribution of the eta meson in the center-of-mass system is isotropic. A qualitative analysis of the Dalitz-plot distribution is presented.
Near threshold K+ K- meson-pair production in proton proton collisions
C. Quentmeier, ..., H.-H. Adam, J. T. Balewski, A. Budzanowski, D. Grzonka, P. Moskal, M. Siemaszko, J. Smyrski et al.
abstract
The near threshold total cross section and angular distributions of K+K? pair production via the reaction pp?ppK+K? have been studied at an excess energy of Q = 17?MeV using the COSY-11 facility at the cooler synchrotron COSY. The obtained cross section as well as an upper limit at an excess energy of Q = 3?MeV represent the first measurements on the K+K? production in the region of small excess energies where production via the channel pp?pp??ppK+K? is energetically forbidden.
Monitoring of the accelerator beam distributions for internal target facilities
P. Moskal, HH. Adam, A. Budzanowski, D. Grzonka, L. Jarczyk, A. Khoukaz, K. Kilian, P. Kowina, N. Lang, T. Lister, W. Oelert, C. Quentmeier, R. Santo, G. Schepers, T. Sefzick, S. Sewerin, M. Siemaszko, J. Smyrski, A. Strzalkowski, M. Wolke, P. Wustner, W. Zipper
abstract
We describe a direct method for monitoring the geometrical dimensions of a synchrotron beam at the target position for internal target installations. The method allows for the observation of the proton beam size as well as the position of the beam relative to the target. As a first demonstration of the technique, we present results obtained by means of the COSY-11 detection system installed at the cooler synchrotron COSY. The influence of the stochastic cooling on the COSY proton beam dimensions is also investigated. (C) 2001 Elsevier Science B.V. All rights reserved.
Proton proton collisions at production thresholds
P. Moskal, ..., H. H. Adam, A. Budzanowski, L. Jarczyk, D. Grzonka, K. Kilian et al.
abstract
Recent results obtained by the COSY-11 collaboration concerning the production of eta and eta' mesons in the pp --> pp Meson reaction are presented. A comparison of the production amplitude for the pi(0), eta and eta' mesons at the same phase space volume allows to conclude that the proton-eta' interaction is in the order of, or smaller than, the proton-pi(0) one. A total cross section determined in a preliminary analysis of the data of elementary kaon and antikaon production via the pp-->ppK(+)K(-) reaction measured at excess energy of Q = 17 MeV is reported.
S - wave eta-prime proton FSI: Phenomenological analysis of near threshold production of pi0, eta, and eta-prime mesons in proton proton collisions
P. Moskal, H.-H. Adam, J.T. Balewski, A. Budzanowski, J. Budzinski, D. Grzonka, L. Jarczyk, M. Siemaszko, J. Smyrski, A. Strzalkowski et al.
abstract
We describe a novel technique for comparing total cross sections for the reactions pp --> pp pi(0), pp --> pp eta, and pp --> pp eta' close to threshold. The initial and final state proton-proton interactions are factored out of the total cross section, and the dependence of this reduced cross section on the volume of phase space is discussed. Different models of the proton-proton interaction are compared. We argue that the scattering length of the S-wave eta'-proton interaction is of the order of 0.1 fm.
Energy dependence of the near threshold total cross-section for the p p -> p p eta-prime reaction
P. Moskal, H.-H. Adam, J.T. Balewski, V. Baru, A. Budzanowski, D. Grzonka, J. Haidenbauer, L. Jarczyk, A. Khoukaz, K. Kilian, M. Koehler, P. Kowina, A. Kudryavtsev, N. Lang, J. Smyrski, A. Strzałkowski et al.
abstract
Total cross sections for the pp --> pp eta' reaction have been measured in the excess energy range from Q = 1.53 MeV to Q = 23.64 MeV. The experiment has been performed at the internal installation COSY-11 using a stochastically cooled proton beam of the COoler SYnchrotron COSY and a hydrogen cluster target. The determined energy dependence of the total cross section weakens the hypothesis of the S-wave repulsive interaction between the eta' meson and the proton. New data agree well with predictions based on the phase-space distribution modified by the proton-proton final-state-interaction (FSI) only.
Near threshold eta meson production in proton proton collisions
J. Smyrski, ..., A. Budzanowski, H. Dombrowski, D. Grzonka, P. Kowina, P. Moskal et al.
abstract
The production of eta mesons has been measured in the proton-proton interaction close to the reaction threshold using the COSY-11 internal facility at the cooler synchrotron COSY. Total cross sections were determined for eight different excess energies in the range from 0.5 MeV to 5.4 MeV. The energy dependence of the total cross section is well described by the available phase-space volume weighted by FSI factors for the proton-proton and proton-eta pairs.
Comparison of Lambda and Sigma 0 Production near Threshold in Proton-Proton Collisions
S. Sewerin, ..., A. Budzanowski, W. Eyrich, C. Goodman, D. Grzonka, L. Jarczyk, K. Kilian, P. Moskal, J. Smyrski et al.
abstract
Threshold measurements of the associated strangeness production reactions pp->pK1L and
pp-> pK1S0 are presented. The most remarkable feature of the data is that at the same excess
energy the total cross section for the S0 production appears to be about a factor of 2816
29 smaller
than for the L particle. It is concluded that strong S0p final state interactions, and in particular the
SN ! Lp conversion reaction, are the likely cause of the depletion in the S signal. This hypothesis
is in line with other experimental evidence in the literature.
On production of eta-prime mesons in p p collisions close to threshold
V. Baru, ..., J. Haidenbauer, J. Speth, P. Moskal et al.
abstract
The near threshold behaviour of the reaction cross section for pp ->pp´
0
, recently measured in
experiments at COSY and SATURNE, is analyzed. The interaction in the pp as well as in the ´
0
p ?nal states
is taken into account. The suppression of the total cross section for this process at excess energies Q < 3
MeV observed in these experiments is interpreted as an evidence for a strong repulsive eta prime p interaction.
Threshold K, eta, and eta' mesons production in p p interaction
P. Moskal, et al.
abstract
Low-energy Lambda - p scattering parameters from the p p -> p K+ Lambda reaction
J. T. Balewski, ..., P. Moskal et al.
abstract
Constraints on the spin-averaged $Lambda p$ scattering length and effective range have been obtained from measurements of the $pp o pK^+Lambda$ reaction close to the production threshold by comparing model phase-space Dalitz plot occupations with experimental ones. The data fix well the position of the virtual bound state in the $Lambda p$ system. Combining this with information from elastic $Lambda p$ scattering measurements at slightly higher energies, together with the fact that the hyperdeuteron is not bound, leads to a new determination of the low energy $Lambda p$ scattering parameters.
Eta-prime production in proton proton scattering close to threshold.
P. Moskal, J. T. Balewski, A. Budzanowski, H. Dombrowski, C. Goodman, D. Grzonka, J. Haidenbauer et al.
abstract
The pp-->ppeta-prime reaction has been measured at the cooler synchrotron COSY at Jülich using the internal beam and the COSY-11 facility. The total cross sections at the four different excess energies Q = 1.5,1.7,2.9, and 4.1 MeV have been evaluated to be sigma = 2.5+-0.5,2.9+-1.1,12.7+-3.2, and 25.2+-3.6nb, respectively. In this region of excess energy the eta-prime cross sections are much lower compared to those of the pi0 and eta production.
Total cross-section of the reaction p p -> p K+ Lambda close to threshold.
J.T Balewski, A Budzanowski, H Dombrowski, W Eyrich, D Grzonka, P. Moskal, C Quentmeier et al.
abstract
The energy dependence of the total cross section for the pp o pK^+Lambda reaction was measured in the threshold region covering the excess energy range up to 7MeV.
Existing model calculations describe the slope of the measured cross sections well, but are too low by a factor of two to three in rate.
The data were used for a precise determination of the beam momentum of the COSY-synchrotron.
Lambda - hyperon production via the pp->pK+ lambda reaction 2 MeV above threshold
J. T. Balewski, ..., P. Moskal, et al.
abstract
The pp -> pK+A reaction was measured at COSY with a proton beam momentum of 2.345 GeVlc, i.e. with an excess
energy of 2 MeV above threshold. The total cross section was determined to be 8.2 i 1.8 nb. The present data point close
to the production threshold indicates, that existing phenomenological parametrizations of the total kaon production cross
section are insufficient.
COSY-11, an internal experimental facility for threshold measurements
S. Brauksiepe, ..., D. Grzonka, K. Kilian, P. Moskal, J. Smyrski, M. Sokolowski, A. Strzałkowski et al.
abstract
The COSY-11 installation is an internal experiment at the cooler synchrotron and storage ring COSY Jülich. It has been designed for full geometrical acceptance close to threshold for meson production studies, especially in the 1 GeV/c2 mass range. The experimental setup makes use of a regular C-type COSY dipole magnet, following a cluster target, to separate reaction products from the beam and to analyze their momenta, thus allowing the observation of charged reaction products at small angles with beam energies close to threshold. Resonances will be identified by missing mass reconstructions from measured four-momenta of two outgoing protons in the predominantly studied pp ? ppX reaction. In addition, charged mesons either produced directly or from decays of X will be detected. The different components of the experimental facility are presented.
A Three layer circular scintillator hodoscope
M. Dahmen, ..., P. Moskal, et al.
abstract
he rotationally symmetric kinematics of hadronic reactions around the beam direction call for a detector system with an appropriate symmetry. A hodoscope has been invented which optimally meets such conditions. A combination of both contrarotating and straight scintillator elements form a three layer circular hodoscope. The overlap of individual counters defines pixels with a structure reminiscent of a sunflower pattern. Thus, a rather large, granulated and flat detector arrangement has been achieved economically. Such hodoscopes are in operation for measurements at LEAR/CERN and CELSIUS/Uppsala. A third enlarged version is presently being tested and will be used in the Time Of Flight spectrometer (TOF) at COSY/Jülich. The performance of individual detector elements and of the complete system was investigated with various particle beams and cosmic rays. Comparisons with Monte Carlo calculations confirm the operation of the detector.
Studies of low-energy K?-nucleus/nuclei interactions with light nuclei by AMADEUS
M. Skurzok, M. Bazzi, M. Bragadireanu, D. Bosnar, M. Cargnelli, A. Clozza, L. De Paolis, R. Del Grande, L. Fabbietti, C. Guaraldo, M. Iliescu, P. Levi Sandri, J. Marton, M. Miliucci, P. Moskal, K. Piscicchia, A. Ramos, A. Scordo, M. Silarski, D. L. Sirghi, F. Sirghi, A. Spallone, O. Vazquez Doce, S. Wycech, J. Zmeskal and C. Curceanu
abstract
The AMADEUS Collaboration aims to provide unique experimental constraints to the antikaon-nucleon strong interaction in the regime of nonperturbative QCD. The K? nuclear captures, both at-rest and in-flight, are studied using the monochromatic low-momentum kaon beam (pK ?120 MeV/c) produced at the DAFNE collider, interacting with the KLOE detector materials. The studies are performed by reconstructing the hyperon-pion and hyperonnucleon final states. In this work a brief description of AMADEUS results for Lambda pi? and Lambda p final states is presented.
Modular J-PET with Improved o-Ps Detection Efficiency for CPT Tests
N. Chug and A. Gajos, On behalf of the J-PET Collaboration
abstract
Ninth Meeting on CPT and Lorentz Symmetry, Bloomington, Indiana, May 17-26, 2022
J-PET is a photon detector built of plastic scintillators, which already has been commissioned for CPT studies in the decays of positronium. In the first experiment, J-PET has achieved a sensitivity to CPT violation at a level of 10^{-4}, and now it aims to reach a level of 10^{-5}. This will be done by enhancing the three-photon registration efficiency for ortho-positronium decays using a new layer of densely packed plastic scintillators termed Modular J-PET. We present the simulation studies performed for different experimental detection setups to be used for the next CPT test with the Modular J-PET detector.
Perspective of CP Violation Search by Modular J-PET Detector in the Ortho-Positronium Decay
K.V. Eliyan, M. Skurzok, P. Moskal
abstract
The positronium atom, a bound state of electron and positron, is a suitable
leptonic test site for Charge-Parity (CP) discrete symmetry research.
According to the Standard Model, the photon?photon interaction in the
final state due to the vacuum polarization may mimic CP violation of the
order of 10^-9, while weak interaction effects lead to a violation of the order
of 10^-14. So far, the experimental limits on CP symmetry violation
in the decay of o-Ps are set at the level of 10^-3. The J-PET detector can
be used to explore discrete symmetries by looking for probable non-zero
expectation values of the symmetry-odd operators, constructed from spin
of ortho-Positronium (o-Ps) and momentum, and polarization vectors of
gamma quanta resulting from o-Ps annihilation. The upgraded version
of the J-PET detector, with an additional fourth layer of detection modules
increases signal acceptance, which allows to triple the efficiency of
quanta detection for CP discrete symmetry studies.
Implementation of the conjugate gradient algorithm for heterogeneous systems
S. Cali, W. Detmold, G. Korcyl, P. Korcyl, P. Shanahan
abstract
Lattice QCD calculations require significant computational effort, with the dominant fraction of resources typically spent in the numerical inversion of the Dirac operator. One of the simplest methods to solve such large and sparse linear systems is the conjugate gradient (CG) approach. In this work we present an implementation of CG that can be executed on different devices, including CPUs, GPUs, and FPGAs. This is achieved by using the SYCL/DPC++ framework, which allows the execution of the same source code on heterogeneous systems.
Estimation of 511 keV Gamma Scatter Fraction in WLS Layer in Total-Body J-PET; A Simulation Study
K. Tayefi Ardebili, S. Niedzwiecki, P. Moskal
abstract
Positron emission tomography (PET) is essential in medical diagnostics and monitoring therapy. The J-PET Collaboration at Jagiellonian University is developing a new generation of Total-Body PET scanners based on plastic scintillators. One of the Total-Body J-PET designs comprises seven rings, each consisting of 24 modules. A single module is built of 2 layers, each comprises of 16 axially arranged plastic scintillator strips of 330 mm length, read out by silicon photomultiplier (SiPM) arrays from both ends, and an additional layer of 50 wavelength shifter (WLS) bars, placed perpendicular to plastic layers. This study estimates the scatter fraction of the Total-Body J-PET manufactured from plastic scintillator strips according to the NEMA NU 2-2018 standards by using the GATE software. The scatter phantom was simulated as a solid cylinder with a length of 700 mm and an outside diameter equal to 203 mm. At the same time, at a radial distance of 45 mm, we have a hole with a diameter of 6.4 mm where a linear source with total activity of 1 MBq is placed. For data processing, sinograms were generated, and the Single Slice Rebinning (SSRB) algorithm was used for the scatter fraction calculation. As a result, we estimate that addition of the WLS layer is increasing the scatter fraction by 0.67%.
The SIDDHARTA-2 experiment: preparation for the first kaonic deuterium measurement
L. De Paolis, M. Bazzi, D. Bosnar, M. Bragadireanu, M. Cargnelli, M. Carminati, A. Clozza, G. Deda, R. Del Grande, K. Dulski, C. Fiorini, I. Friščić, C. Guaraldo, M. Iliescu, M. Iwasaki, P. King, A. Khreptak, P. Levi Sandri, S. Manti, J. Marton, M. Miliucci, P. Moskal, F. Napolitano, S. Niedźwiecki, H. Onishi, K. Piscicchia, Y. Sada, A. Scordo, F. Sgaramella, H. Shi, M. Silarski, D. L. Sirghi. F. Sirghi, M. Skurzok, A. Spallone, K. Toho, M. Tüchler, C. Yoshida, J. Zmeskal and C. Curceanu
abstract
The SIDDHARTA-2 experiment aims to perform the first measurement of the kaonic deuterium 2p -> 1s x-ray transitions. The apparatus is presently installed at the interaction region of the DAFNE electron-positron collider at the National Laboratories of Frascati (LNF-INFN), in Italy. Kaonic deuterium and kaonic hydrogen 2p -> 1s x-ray transitions measurements, the latter one already performed by the SIDDHARTA collaboration, allow the determination of antikaon-nucleon scattering lengths. A description of the SIDDHARTA-2 apparatus in preparation for the kaonic deuterium measurement is provided in this paper.
Towards Improving the Sensitivity of the CPT Symmetry in Positronium Decays with the Modular J-PET Detector
N. Chug, A. Gajos
abstract
The Jagiellonian Positron Emission Tomograph (J-PET) is the first plastic scintillator-based tomographic device used to test discrete symmetries in the charged leptonic sector. One of such tests is for the CPT symmetry, under the combined transformation of charge, parity, and time reversal in the decays of positronium atoms. J-PET performed its first measurement for the CPT symmetry test by searching for non-vanishing CPT-violating angular correlations between the spin and orientation of the decay plane of ortho-positronium (o-Ps) atoms, which is the triplet state of positronium. The sensitivity of testing CPT symmetry with the J-PET detector reaches the precision level of 10?4. Here, we will discuss the prospects of improving the sensitivity of this test beyond the level of 10?4 by enhancing the photon registration efficiency using a new layer of densely packed plastic scintillators and a spherical annihilation chamber as a positronium production medium.
Trigger rejection factor in the first kaonic helium run with the complete SIDDHARTA-2 setup
L. De Paolis, M. Bazzi, D. Bosnar, M. Bragadireanu, M. Cargnelli, M. Carminati, A. Clozza, G. Deda, R. Del Grande, L. Fabbietti, C. Fiorini, I. Friščić, C. Guaraldo, M. Iliescu, M. Iwasaki, A. Khreptak, P. King, P. Levi Sandri, S. Manti, J. Marton, M. Miliucci, P. Moskal, F. Napolitano, S. Niedźwiecki, H. Onishi, K. Piscicchia, Y. Sada, A. Scordo, F. Sgaramella, H. Shi, M. Silarski, D. L. Sirghi. F. Sirghi, M. Skurzok, A. Spallone, K. Toho, M. Tüchler, C. Yoshida, J. Zmeskal and C. Curceanu
abstract
The SIDDHARTA-2 experiment aims to perform the first measurement of the kaonic deuterium 2p -> 1s x-ray transition energy. Such measurement, together with the measurement of kaonic hydrogen 2p -> 1s x-ray energy transition performed by the SIDDHARTA experiment in 2011, allows the determination of kaon proton and kaon neutron scattering lengths and represents a fundamental input for the low energies QCD in the strangeness sector theory. The SIDDHARTA-2 experiment is presently installed at the DAFNE electronpositron collider at the National Laboratories of Frascati, in Italy. In May 2022, the kaonic 4He x-ray transitions measurement was performed by the complete SIDDHARTA-2 setup, by using a gaseous target. The result of this measurement is presented in this paper, with a specific focus on the background rejection performed by the kaon trigger system.
Developing a phantom for the positronium imaging evaluation
G. Łapkiewicz, S. Niedźwiecki, P. Moskal
abstract
In this contribution, a concept for a new phantom for positronium imaging
with PET scanners is described. The proposed phantom is based on
the NEMA IEC phantom in which six high-activity spheres are filled with
solutions characterized by a different mean ortho-positronium lifetime. A
method for controlling ortho-positronium lifetime is discussed along with
preliminary results. The XAD4 suspended in various fractions of water was
tested as a potential model of a sample with a controlled mean lifetime of
ortho-positronium. The mean lifetime of ortho-positronium for six samples
was estimated by means of the Positronium Annihilation Lifetime Spectroscopy
(PALS). Obtained spectra were fitted with the PALS Avalanche
analysis program and components corresponding to the ortho-positronium
annihilation in the XAD4 pores were established. As a result, the correlations
between the lifetime and production intensity of ortho-positronium
and the concentration of XAD4 in water were determined.
Studies of the Linearity and Stability of Silicon Drift Detectors for Kaonic Atoms X-ray Spectroscopy
A. Khreptak, C. Amsler, M. Bazzi, D. Bosnar, M. Bragadireanu, M. Cargnelli, M. Carminati, A. Clozza, G. Deda, L. De Paolis, R. Del Grande, L. Fabbietti, C. Fiorini, C. Guaraldo, M. Iliescu, M. Iwasaki, S. Manti, J. Marton, M. Miliucci, P. Moskal, F. Napolitano, S. Niedźwiecki, H. Onishi, K. Piscicchia, Y. Sada, A. Scordo, F. Sgaramella, H. Shi, M. Silarski, D. Sirghi, F. Sirghi, M. Skurzok, A. Spallone, K. Toho, M. Tüchler, O. Vazquez Doce, J. Zmeskal, C. Yoshida, C. Curceanu
abstract
The SIDDHARTA-2 experiment at the DAFNE collider aims to perform
precision measurements of kaonic atoms X-ray spectroscopy for the
investigation of the antikaon?nucleon strong interaction. To achieve this
goal, novel large-area Silicon Drift Detectors (SDDs) have been developed.
These devices have special geometry, field configuration, and readout electronics
that ensure excellent performance in terms of linearity and stability.
The paper presents preliminary results for the linearity determination and
stability monitoring of the SDDs system during the measurement of kaonic
deuterium carried out in the summer of 2022.
Testing CPT symmetry in ortho-positronium decays with J-PET detector
A. Gajos
abstract
Search for possible violation of combined charge, parity, and time-reversal symmetries is yet another approach for a test of New Physics, therefore a bound state of electron and positron (positronium) as the lightest matter-antimatter system and at the same time an eigenstate of the C and P operators is an unique probe in such endeavour. The test is performed by measurement of angular correlations in the annihilations of the lightest leptonic bound system. With the Jagiellonian Positron Emission Tomograph (J-PET) we have collected an unprecedented range of kinematical configurations of exclusively-recorded annihilations of the positronium triplet state (ortho-positronium) into three photons. Employing a novel technique for estimation of positronium spin axis on the basis of a single event, we determined the complete distribution of an angular correlation between spin and annihilation plane of ortho-positronium. We present recently published result of determined expectation value of this correlation at the precision level of 10^{-4}, with an over three-fold improvement on the previous measurement. We discuss also the prospects for reaching the precision level of 10^{-5} with the CPT symmetry test at the J-PET detector.
Potential of modular J-PET for applications in the field of particle and medical physics
S. Sharma, K. Kacprzak, K. Dulski, S. Niedźwiecki, P. Moskal
abstract
Modular J-PET is the new prototype of the Jagiellonian Positron Emission Tomograph. The portability feature due to its modular design makes it a unique tomograph with a larger axial field of view of 50 cm. The complete ring is composed of 24 modules that can be configured as a diagnostic chamber with a diameter of approximately 76 cm or as a detection setup consisting of several modules for experimental studies where multiple photons are generated in a single event. The J-PET collaboration explicitly studies the decays of the positronium atom (Ps), which is a bound state of electron and positron that self-annihilate into multiple photons. The modular J-PET provides a significant phase space covrage for the registration of photons originating from the decays of Ps atoms. In this paper, we discuss the properties of the modular J-PET and its potential applications in medical and particle physics.
Positronium and Quantum Entanglement Imaging: A New Trend in Positron Emission Tomography
P. Moskal
abstract
We report on the progress in the development of positronium imaging and quantum entanglement imaging achieved
thus far by the J-PET collaboration. Positronium (a bound state of electron and positron) is copiously produced in the human
body during positron emission tomography. Its properties depend on the size of the intra-molecular voids and concentration in them of molecules as e.g. molecular oxygen. Therefore, positronium may serve as a biomarker of tissue pathology and hypoxia.
Recently, the positronium imaging method was developed and the first positronium images of phantoms comprised of tumor
cardiac myxoma and healthy adipose tissues were created by means of the J-PET tomograph. A significant difference in mean
positronium lifetime in cardiac myxoma and adipose tissues opens promising perspectives for the application of positronium
as a cancer diagnostic indicator. It is also important to note that photons originating from the decay of positronium are
quantum entangled in polarisation. Thus, it can be hypothesized that by measuring the degree of entanglement of photons from
positronium annihilation, additional information can be obtained about the molecular environment in which the positronium is
formed. J-PET is the first PET system enabling the determination of linear polarisation of annihilation photons. The measurements
performed with the J-PET detector confirm that the distribution of relative angle between the polarization of 511 keV back-toback
photons is consistent with the assumption that these photons are quantum entangled. These results open up prospects for the
study of quantum entanglement of photons from positronium annihilation in living organisms.
Quantum Sensing for Biomedical Applications
K. Shimazoe, H. Tomita, D. Watts, P. Moskal, A. Kagawa, P.G. Thirolf, D. Budker, C.S. Levin
abstract
Quantum technology, such as the quantum computers, has attracted significant attention in recent years. In nuclear medicine, powerful and highly sensitive molecular imaging modalities such as PET (Positron Emission Tomography), SPECT (Single Photon Emission CT) and MRI (Magnetic Resonance Imaging) provide accurate morphological and functional information. Exploiting certain aspects of quantum mechanics may bring further improvements in sensitivity, spatial resolution and enable novel capabilities in the field of biomedical imaging and sensing. In this workshop, the possibilities of biomedical applications inspired by quantum technology were discussed. The following exciting topics were covered: quantum entanglement in PET, dynamic nuclear polarization toward more sensitive MRI, quantum sensors based on the 229mTh nuclear clock, plans of an advanced high-energy gamma-ray source at CERN, laser-assisted radiation detection, solid-state quantum sensors such as those based on nitrogen vacancy centers in diamond, quantum sensing using cascade multi photons, and a laser-based radioactive isotope analysis.
Status and perspectives for low energy kaon-nucleon interaction studies at DAFNE: from SIDDHARTA to SIDDHARTA-2
F. Sirghi, M. Bazzi, D. Bosnar, M. Bragadireanu, M. Cargnelli, A. Clozza, C. Curceanu, G. Deda, L. De Paolis, R. Del Grande, C. Fiorini, C. Guaraldo, M. Iliescu, M. Iwasaki, P. King, P. Levi Sandri, J. Marton, M. Miliucci, P. Moskal, F. Napolitano, S. Niedźwiecki, K. Piscicchia, A. Scordo, F. Sgaramella, H. Shi, M. Silarski, D. Sirghi, F. Sirghi, M. Skurzok, A. Spallone, M. Tüchler, O. Vazquez Doce, J. Zmeskal
abstract
The study of the antikaon nucleon system at very low energies plays a key role for the understanding
of the strong interaction between hadrons in the strangeness sector. The information provided
by the low energy kaon- nucleon interaction is accessible through the study of kaonic atoms.
The lightest atomic systems, namely the kaonic hydrogen and the kaonic deuterium, provide the
isospin dependent kaon-nucleon scattering lengths by measuring the X-rays emitted during their
de-excitation to the 1s level. Until now, the most precise kaonic hydrogen measurement and an
exploratory measurement of kaonic deuterium were carried out at the DA?NE collider by the
SIDDHARTA collaboration, combining the excellent quality kaon beam delivered by the collider
with new experimental techniques, as fast and very precise X-ray detectors, like the Silicon Drift
Detectors. Today, the most important experimental information missing in the field of the lowenergy antikaon-nucleon interactions is the experimental determination of the hadronic energy
shift and width of kaonic deuterium, and will be measured by the new SIDDHARTA-2 experiment,
which is installed in DA?NE and is ready to start the data taking campaign.
Introduction of the DOI capable Total-Body J-PET, a simulation study
M. Dadgar, S. Parzych, F. Tayefi, P. Moskal, S. Vandenberghe
abstract
Positron Emission Tomography PET plays a fundamental role in medical diagnosis and oncological research. Due to exceptional performance of PET scanners and continuous advancement, their clinical availability is spreading [1]. The development of Total-Body PET technology is one of the most recent trends in the medical imaging field. Having large axial field of view (AFOV), they provide greater detection area and therefore an increased sensitivity [2]. Nevertheless, alongside many advantages over traditional PET tomographs they are more susceptible to the parallax error, which causes degradation of axial resolution. This is caused by the contribution of most oblique lines of response (LORs) in the acquired data. To overcome this problem the application of a cut ? angular acceptance criterion ? over such LORs has been recommended. Nonetheless, it causes a significant loss of scanner?s sensitivity [3].Jagiellonian PET (J-PET) collaboration from Krakow, Poland is currently developing novel PET tomographs based on the organic, plastic scintillators [4, 1]. Such unique design allows not only for the introduction of cost efficient Total-Body system, but also is able to solve challenges connected with such tomographs. The main aim of this study is to present a novel solution to overcoming the aforementioned problem of degradation in axial resolution in Total-Body scanners by introducing DOI capable detectors based on the J-PET technology.
High precision Kaonic Deuterium measurement at the DAFNE collider: theSIDDHARTA-2 experiment and the SIDDHARTINO run
M. Miliucci, M. Bazzi, D. Bosnar, M. Bragadireanu, M. Carminati, M. Cargnelli, A. Clozza, C. Curceanu, G. Deda, L. De Paolis, R. Del Grande, C. Fiorini, C. Guaraldo, M. Iliescu, M. Iwasaki, P. King, P. Levi Sandri, J. Marton, P. Moskal, F. Napolitano, S. Niedźwiecki, K. Piscicchia, A. Scordo, F. Sgaramella, H. Shi , M. Silarski, D. Sirghi, F. Sirghi, M. Skurzok, A. Spallone, M. T ?uchler, O. Vazquez Doce, J. Zmeskal
abstract
The kaonic deuterium 2p?1s transition X-ray measurement, a fundamental information needed for a deeper understanding of the QuantumChromoDynamics (QCD) in the strangeness sector, is still missing. The SIDDHARTA-2 collaboration is now ready to achieve this unprece-dented result thanks to the dedicated experimental apparatus that will allow to obtain the values of the kaonic deuterium K-transitions witha precision comparable to the most precise kaonic hydrogen measurement to-date performed by SIDDHARTA in 2009. Both the kaonichydrogen and kaonic deuterium X-ray spectroscopy measurements of the de-excitation towards the fundamental level are a direct probe onKN interaction at threshold, as opposed to the scattering experiments which need an extrapolation to zero energy. Combining these resultsthrough the Deser-Truemann like formula, the isospin-dependent kaon-nucleon scattering lengths can be obtained in a model-independentway. The SIDDHARTA-2 setup is presently installed at the DAFNE (Double Annular Phi Factory for Nice Experiments) collider of IstitutoNazionale di Fisica Nucleare- Laboratori Nazionali di Frascati and it is ready to perform the challenging kaonic deuterium measurement. Thispaper provides an overview on the SIDDHARTA-2 experimental apparatus and a preliminary result of the kaonic helium run, preparatory forthe SIDDHARTA-2 data taking campaign, is also presented.
Recent results on the positronium decay studies with the J-PET detector
E. Czerwinski, J. Raj
abstract
Positronium, as a bound state of electron and positron and the light- est matter-antimatter system and at the same time an eigenstate of the C and P operators is a unique probe to search for possible violation of combined charge, parity, and time-reversal symmetries (CPT). The test is performed by a measure- ment of angular correlations in the annihilations of the lightest leptonic bound system. The J-PET detector is the only device which enables the determina- tion of the polarization of photons from positronium annihilation together with the positronium spin axis on an event-by-event basis. This allows to explore a new class of discrete symmetry odd operators that were not investigated before. The first test of CPT symmetry at J-PET is presented together with preliminary results of CP, P and T symmetry test.
Main Features of the SIDDHARTA-2 Apparatus for Kaonic Deuterium X-Ray Measurements
M. Tüchler, F. Sirghi, M. Bazzi, D. Bosnar, M. Bragadireanu, M. Carminati, M. Cargnelli, A. Clozza, C. Curceanu, G. Deda, R. Del Grande, L. De Paolis, C. Fiorini, C. Guaraldo, M. Iliescu, M. Iwasaki, P. King, P. Levi Sandri, J. Marton, M. Miliucci, P. Moskal, F. Napolitano, S. Niedzwiecki, K. Piscicchia, A. Scordo, F. Sgaramella, H. Shi, M. Silarski, D. Sirghi, M. Skurzok, A. Spallone, O. Vazquez Doce, E. Widmann, J. Zmeskal
abstract
The low-energy, non-perturbative regime of QCD can be studied directly by X-ray spectroscopy of light kaonic atoms. The SIDDHARTA-2 experiment, located at the DAFNE collider, aims to measure the 2p -> 1s transition in kaonic deuterium for the first time to extract the antikaon-nucleon scattering lengths. This measurement is impeded, inter alia, by the low K?d X-ray yield. Hence, several updates have been implemented on the apparatus to increase the signal-to-background ratio, which are discussed in detail in this paper: a lightweight gas target cell, novel Silicon Drift Detectors for the X-ray detection with excellent performance, and a veto system for active background suppression. The experiment has undergone a first preparatory run during DAFNE?s commissioning phase in 2021, concluding with a successful kaonic helium measurement.
Low energy kaon-nuclei interaction studies at DAFNE
K. Piscicchia, M. Cargnelli, R. Del Grande, L. Fabbietti, J. Marton, P. Moskal, A. Scordo, D. Sirghi, M. Skurzok, O. Vazquez Doce, S. Wycech, J. Zmeskal, P. Branchini, E. Czerwinski, V. De Leo, E. De Lucia, A. Di Cicco, E. Diociaiuti, P. Fermani, S. Fiore, M. Martini, E. Perez Del Rio, A. Selce, M. Silarski, C. Curceanu
abstract
The aim of the AMADEUS experiment is to investigate the lowenergy antikaon interaction with nucleons and nuclei, exploiting the unique lowmomentum beam of kaons produced by the DAFNE collider at LNF-INFN, to constrain hadronic nuclear physics models in the strangeness -1 sector. As a first step the data collected in 2004/2005 by the KLOE collaboration, consisting in a complex of K- absorptions in H, 4He, 9Be and 12C, was analyzed, leading to the first invariant mass spectroscopic study with very low momentum (about 100 MeV) in-flight K- captures. A dedicated pure Carbon target was also implemented in the central region of the KLOE detector, providing a high statistic reference sample of pure at-rest K- nuclear interaction. The first measurement of the non-resonant transition amplitude at MeV below the threshold is presented, in relation with the Lambda(1405) properties studies.
CPT symmetry test in positronium annihilations with the J-PET detector
N. Chug and A. Gajos, On behalf of the J-PET collaboration
abstract
Discrete symmetry under combined transformation of charge, parity and time reversal (CPT) can be tested in the decays of positronium atom, the lightest bound system built of charged leptons. Jagiellonian Positron Emission Tomograph (J-PET) device constructed from plastic scintillators, detects the photons originating from electron positron annihilation. This feature enables J-PET to
study CPT symmetry in the three photon annihilations of the triplet state of positronium. Signs of violation of the CPT symmetry can be sought as a non-vanishing expectation value of an angular correlation operator that is odd under CPT transformation. A technique to estimate the spin of ortho-positronium and momenta of annihilation photons for single recorded ortho-positronium
annihilation events allows J-PET to measure the expectation value of a CPT symmetry odd angular correlation operator. J-PET measures a broad range of kinematical configurations of ortho-positronium annihilation to three photons and is the first experiment to determine the full range of the CPT-odd angular correlation.
From tests of discrete symmetries to medical imaging with J-PET detector
P. Moskal, J. Baran, N. Chug, C. Curceanu, E. Czerwiński, M. Dadgar, K. Dulski, J. Gajewski, A. Gajos, M. Gorgol, B.C. Hiesmayr, B. Jasińska, K. Kacprzak, Ł. Kapłon, H. Karimi, K. Klimaszewski, P. Konieczka, G. Korcyl, T. Kozik, N. Krawczyk, W. Krzemień, E. Kubicz, D. Kumar, S. Niedźwiecki, D. Panek, S. Parzych, E. Perez del Rio, L. Raczyński, J. Raj, A. Ruciński, S. Sharma, Shivani, R.Y. Shopa, M. Silarski, M. Skurzok, E.Ł. Stępień, M. Szczepanek, F. Tayefi, W. Wiślicki
abstract
We present results on CPT symmetry tests in decays of positronium performed with the precision at the level of 10?4, and positronium images determined with the prototype of the J-PET tomograph. The first full-scale prototype apparatus consists of 192 plastic scintillator strips readout from both ends with vacuum tube photomultipliers. Signals produced by photomultipliers are probed in the amplitude domain and are digitized by FPGA-based readout boards in triggerless mode. In this contribution we report on the first two- and three-photon positronium images and tests of CPT symmetry in positronium decays.
Kaonic atoms measurements at the DAFNE collider: the SIDDHARTA-2 experiment
Catalina Curceanu, Marco Miliucci, Massimiliano Bazzi, Damir Bosnar, Mario Bragadireanu, Marco Carminati, Michael Cargnelli, Alberto Clozza, Griseld Deda, Luca De Paolis, Raffaele Del Grande, Carlo Fiorini, Carlo Guaraldo, Mihail Iliescu, Masahiko Iwasaki, Pietro King, Paolo Levi Sandri, Johann Marton, Paweł Moskal, Fabrizio Napolitano, Szymon Niedźwiecki, Kristian Piscicchia, Alessandro Scordo, Francesco Sgaramella, Hexi Shi, Michał Silarski, Diana Sirghi, Florin Sirghi, Magdalena Skurzok, Antonio Spallone, Marlene Tüchler, Oton Vazquez Doce, Johann Zmeskal
abstract
The X-ray spectroscopy measurements of light kaonic atoms? deexcitation towards the fundamental level provide unique information on the low-energy Quantum ChromoDynamics (QCD) in the strangeness sector, being a direct probe of the kaon/nucleon interaction at threshold, unobtainable through the scattering experiments. In this framework, the SIDDHARTA-2 collaboration is going to perform the first kaonic deuterium 2p -> 1s transition measurement at the DAFNE collider of Istituto Nazionale di Fisica Nucleare - Laboratori Nazionali di Frascati. Combining this measurement with the kaonic hydrogen one performed by SIDDHARTA in 2009 it will be possible to obtain, in a model-independent way, the isospin-dependent antikaon-nucleon scattering lengths. The paper introduces the SIDDHARTA-2 setup, an upgraded version with respect to the one used for the kaonic hydrogen measurement, dedicated to the ambitious kaonic deuterium measurement, together with the preliminary results obtained during the kaonic helium run, preparatory for the SIDDHARTA-2 data taking campaign.
Positronium life-time as a new approach for cardiac masses imaging
E. Stępień E. Kubicz, G. Grudzień, K. Dulski, B. Leszczyński, P. Moskal
abstract
Probing low-energy QCD with kaonic atoms at DAFNE
M. Tuchler, J. Zmeskal, A. Amirkhani, C. Amsler, A. Baniahmad, M. Bazzi, D. Bosnar, M. A. Bragadireanu, P. Buhler, M. Cargnelli, M. Carminati, A. Clozza, C. Curceanu, R. Del Grande, L. De Paolis, L. Fabbietti, C. Fiorini, C. Guaraldo, M. Iliescu, M. Iwasaki, P. Levi Sandri, J. Marton, M. Miliucci, P. Moskal, S. Niedzwiecki, S. Okada, K. Piscicchia, A. Scordo, M. Silarski, D. Sirghi, F. Sirghi, M. Skurzok, A. Spallone, O. Vazquez Doce and E. Widmann
abstract
X-ray spectroscopy of kaonic atoms provides a versatile tool to study the strong interaction at low energies via a direct observation of its influence on the ground state of kaonic hydrogen atoms. The SIDDHARTA experiment provided precise results on the energy shift and width of the kaonic hydrogen 1s state induced by the strong interaction. To enable the extraction of the antikaon-nucleon scattering lengths a0 and a1, SIDDHARTA-2 aims to determine the energy shift and width in kaonic deuterium with precisions of 30 eV and 75 eV, respectively. This measurement is aggravated by the low kaonic deuterium X-ray yield and a high background environment and will only be possible by implementing a severe upgrade on the SIDDHARTA apparatus.
Search for eta'-mesic nuclei using (p, d) reaction with FRS/Super-FRS at GSI/FAIR
Y. K. Tanaka, S. Bagchi, J. Benlliure, T. Dickel, V. Drozd, H. Ekawa, H. Fujioka, H. Geissel, F. Goldenbaum, C. Guo, E. Haettner, M. N. Harakeh, R.S. Hayano, S. Hirenzaki, C. Hornung, Y. Igarashi, N. Ikeno, K. Itahashi, M. Iwasaki, D. Jido, N. Kalantar-Nayestanaki, R. Kanungo, B. Kindler, R. Knöbel, D. Kostyleva, N. Kurz, N. Kuzminchuk, B. Lommel, Y. Ma, S. Y. Matsumoto, V. Metag, S. Minami, P. Moskal, I. Mukha, T. Nagae, H. Nagahiro, M. Nakagawa, H. J. Ong, H. Outa, S. Pietri, W. R. Plass, A. Prochazka, S. Purushothaman, C. Rappold, J. Ritman, J.L. Rodríguez-Sánchez, R. Ruber, O. Rundel, T. R. Saito, C. Scheidenberger, R. Sekiya, V. Serdyuk, H. Simon, B. Sitar, M. Skurzok, P. Strmen, B. Sun, I. Szarka, M. Takechi, I. Tanihata, S. Terashima, H. Weick, A. Yamamoto and J. Zhao
abstract
We plan a semi-exclusive measurement of the 12 C (p, dp) reaction to search for eta'-mesic nuclei, aiming at investigating in-medium properties of the eta'-meson. We employ a 2.5 GeV proton beam impinging on a carbon target to produce eta'-mesic 11 C nuclei via the 12 C (p, d) eta' 11 C reaction. Using coincidence measurements of the forward going deuterons, important for missing-mass spectroscopy, and decay protons emitted from the eta'-mesic nuclei. for event selection will provide a high experimental sensitivity to observe eta'-mesic nuclei. We will perform the measurements by combining the WASA detector system with the fragment separator FRS at GSI and also with the Super-FRS at FAIR in the future. The plan of the experiments and the present status are reported.
Studies of K--nuclei interactions at low-energies by AMADEUS
R. Del Grande, M. Bazzi, A. M. Bragadireanu, D. Bosnar, M. Cargnelli, A. Clozza, C. Curceanu, L. De Paolis, L. Fabbietti, F. Ghio, C. Guaraldo, M. Iliescu, M. Iwasaki, P. Levi Sandri, J. Marton, M. Miliucci , P. Moskal, S. Okada, K. Piscicchia, A. Ramos, A. Scordo, M. Silarski, D. L. Sirghi, F. Sirghi, M. Skurzok, A. Spallone, O. Vazquez Doce, E. Widmann, S. Wycech , J. Zmeskal
abstract
The AMADEUS collaboration is providing unique experimental information on the low-energy strong interaction between K- and nucleons exploiting the low momentum K- (pK ~ 127 MeV/c) produced at the DAFNE collider and using the KLOE detector as active target. The absorption of the K- in light nuclei (H, 4He, 9Be and 12C) are investigated and hyperon-pion/hyperon-nucleons, emitted in the final state, are reconstructed. In the present work the results obtained from the study of Lambda pi-, Lambda p and Lambda t correlated production will be presented.
Analysis of the pd->pdpi0 Reaction Measured with WASA-at-COSY Facility in Order to Search for eta-mesic Helium
A. Khreptak, M. Skurzok, O. Rundel, P. Moskal
abstract
In this report, we briefly present the preliminary results of the search for 3He-eta bound system in pd->p d pi0 reaction.
Recent AMADEUS Studies of Low-Energy K--Nucleus/Nuclei Interactions
M. Skurzok, M. Bazzi, M. A. Bragadireanu, D. Bosnar, M. Cargnelli, C. Curceanu, L. De Paolis, R. Del Grande, L. Fabbietti, C. Fiorini, C. Guaraldo, M. Iliescu, P. Levi Sandri, J. Marton, M. Miliucci, P. Moskal, K. Piscicchia, A. Ramos, A. Scordo, M. Silarski, D. Laura Sirghi, F. Sirghi, A. Spallone, O. Vazquez Doce, E. Widmann, S. Wycech, J. Zmeskal
abstract
We briefly report the recent results obtained by the AMADEUS collaboration on experimental studies of the K- low-energy interactions with light nuclei and outline the future perspectives.
Influence of Cosmic Radiation while Testing the Time Reversal Symmetry in the Decay of Ortho-Positronium Atoms using the J-PET detector
J. Raj, E. Czerwiński
abstract
This article reports the influence of cosmic radiation interaction while testing the T-symmetry in metastable triplet states of positronium with the Jagiellonian-Positron Emission Tomograph (J-PET) detector. The J-PET detector developed at Jagiellonian University in Krakow, Poland is one of its kind being based on organic scintillators. J-PET is an axially symmetric and high acceptance scanner that can be used as a multi-purpose detector system. It is well suited to pursue tests of discrete symmetries in decays of positronium in addition to medical imaging. Cosmic rays have been considered as a well known source of background
while performing test measurements with the J-PET detector. It is important to estimate and reject the significant contribution of the cosmic ray interactions within the J-PET detector in order to improve the sensitivity while testing T-symmetry violation. Therefore, the results of cosmic radiation uniquely being separated due to their large energy deposits in plastic scintillator detectors are shown in this article.
Tests of discrete symmetries in positronium decays with the J-PETdetector
E. Czerwiński
abstract
The newly constructed Jagiellonian Positron Emission Tomograph (J-PET) is the first tomograph built from plastic scintillators. As a detector optimized for the registration of photons from the electron-positron annihilations, it also capable to tests discrete symmetries in decays of positronium atoms via the determination of the expectation values of the discrete-symmetries-odd operators, which may be constructed from the spin of the ortho-positronium atom and the momenta and polarization vectors of photons originating from its annihilation.
Low-energy Kaon Nucleon/Nuclei Studies at DAFNE: the SIDDHARTA-2 Experiment
M. Miliucci, A. Amirkhani, A. Baniahmad, M. Bazzi, D. Bosnar, M. Bragadireanu, M. Carminati, M. Cargnelli, C. Curceanu, A. Clozza, L. De Paolis, R. Del Grande, L. Fabbietti, C. Fiorini, C. Guaraldo, M. Iliescu, M. Iwasaki, P. Levi Sandri, J. Marton, P. Moskal, S. Niedźwiecki, S. Okada, K. Piscicchia, A. Scordo, H. Shi, M. Silarski, D. Sirghi, F. Sirghi, M. Skurzok, A. Spallone, M. Tüchler, O. Vazquez Doce, J. Zmeskal
abstract
The experimental studies of light kaonic atoms offer the unique opportunity to investigate the kaon-nucleus interaction at threshold, performing experiments equivalent to scattering at vanishing relative energies without the need of an extrapolation. In this framework, the SIDDHARTA-2 experiment is going to perform the first measurement of kaonic deuterium 2p->1s transition, which is fundamental to extract the isospin-dependent antikaon-nucleon scattering lengths. The setup was installed on the DAFNE collider of LNF-INFN in spring 2019 and is presently in optimization phase. The SIDDHARTA-2 data taking campaign for the kaonic deuterium is planned in 2020-2021.
Studies of kaonic atoms at the DAFNE collider: from SIDDHARTA to SIDDHARTA-2
D. Sirghi, A. Amirkhani, A. Baniahmad, M. Bazzi, D. Bosnar, M. Bragadireanu, M. Carminati, M. Cargnelli, A. Clozza, C. Curceanu, L. De Paolis, R. Del Grande, L. Fabbietti, C. Fiorini, C. Guaraldo, M. Iliescu, M. Iwasaki, P. Levi Sandri, J. Marton, M. Miliucci, P. Moskal, S. Niedźwiecki, S. Okada, D.Pietreanu, K. Piscicchia, A. Scordo, M. Silarski, F. Sirghi, M. Skurzok, A. Spallone, M. Tüchler, O. Vazquez Doce, E. Widmann, J. Zmeskal
abstract
The DA?NE electron-positron collider of the Laboratori Nazionali di Frascati of INFN is a worldwide unique low-energy kaon source and for this reason is suitable for low-energy kaon physics like kaonic atoms and kaon-nucleons/nuclei interaction studies. Kaonic atoms are atomic systems where an electron is replaced by a negatively charged kaon, containing the strange quark, which interacts in the lowest orbits with the nucleus also by the strong interaction. As a result, their study offers the unique opportunity to perform experiments equivalent to scattering at vanishing relative energy. This allows to study the strong interaction between the antikaon and the nucleon or the nucleus at threshold, without the need of ad hoc extrapolation to zero energy, as in scattering experiments. The most precise kaonic hydrogen measurement to date, together with an exploratory measurement of kaonic deuterium, were carried out by the SIDDHARTA collaboration at the DA?NE electron-positron collider of LNF-INFN, by combining the excellent quality kaon beam delivered by the collider with new experimental techniques, as fast and precise Silicon-Drift X-ray Detectors. The measurement of kaonic deuterium will be realized in the near future by SIDDHARTA-2, a major upgrade of SIDDHARTA.
Studies of low-energy K- hadronic interactions with light nuclei by AMADEUS
R. Del Grande, M. Bazzi, A. M. Bragadireanu, D. Bosnar, M. Cargnelli, A. Clozza, C. Curceanu, L. De Paolis, L. Fabbietti, F. Ghio, C. Guaraldo, M. Iliescu, M. Iwasaki, P. Levi Sandri, J. Marton, M. Miliucci, P. Moskal, S. Okada, K. Piscicchia, A. Ramos, A. Scordo, M. Silarski, D .L. Sirghi, F. Sirghi, M. Skurzok, A. Spallone, O. Vazquez Doce, E. Widmann, S. Wycech and J. Zmeskal
abstract
The AMADEUS collaboration aims to provide precise experimental information on the K- strong interaction with nucleons in the low-energy regime. The step 0 of AMADEUS consists of the re-analysis of the data collected with the KLOE detector at the DA?NE collider during the 2004/2005 data taking campaign. The absorptions of low-momentum K?s in the nuclei contained in the detector and the beam pipe setup (H,4He,9Be and12C) are investigated. Information on the K- single and multi-nucleon interactions are extracted from the study of the Lambda-pi- and p correlated production in the final state.
Test of CPT Symmetry with Positronium at the J-PET Detector
E. Czerwiński
abstract
The Jagiellonian Positron Emission Tomograph (J-PET) is the first tomograph built from plastic scintillators capable to test CPT symmetry in decays of positronium atoms. This test is performed via the determination of the expectation value of operators that are odd under discrete symmetries. The J-PET detector is optimized for the registration of photons from electron-positron annihilations, and such operators may be constructed from the spin of ortho-positronium atoms and the momenta and polarization vectors of photons originating from its annihilation.
Positronium Imaging
P. Moskal
abstract
During the positron emission tomography about 40% of positrons annihilations occur through the creation of positronium which may be trapped within and between molecules. Positronium decays in the patient body are sensitive to the nanostructure and metabolism of the tissues. This phenomenon is not used in the present PET diagnostics, yet it is in principle possible to use environment modified properties of positronium as diagnostic biomarkers for cancer therapy. First in-vitro studies show differences of positronium mean lifetime and production probability in the healthy and cancerous tissues, indicating that they may be used as indicators for in-vivo cancer classification. Here we present a method of positronium lifetime imaging in which the lifetime and position of positronium atoms is determined on an event-by-event basis. The method requires application of beta+ decaying isotope emitting prompt gamma (e.g. 44 Sc). We discuss the possibility of determining the time and position of positronium annihilation from the back-to-back photons originating from the interaction of positronium with the surrounding atoms and bio-active molecules. The prompt gamma is used for the determination of the time of the formation of positronium. We estimate that with the total-body PET scanners the sensitivity of the positronium lifetime imaging, which requires coincident registration of the back-to-back annihilation photons and the prompt gamma is comparable to the sensitivities for the metabolic imaging with standard PET scanners.
Study of Three-Nucleon Dynamics in the dp breakup collisions using the WASA detector
P. Adlarson, ..., E. Czerwiński, O. Khreptak, W. Krzemień, P. Moskal, O. Rundel, I. Schätti-Ozerianska, M. Skurzok, M.J. Zieliński, et al.
abstract
Differential cross section for the 1H(d,pp)n breakup reaction at deuteron beam energy of 340 MeV has been measured with the use of WASA detector at COSY-Juelich. The set of proton-proton coincidences registered at Forward Detector has been analysed on dense grid of kinematic variables, giving in total around 5600 data points. The cross section data are compared to theoretical predictions based on the state-of-the-art nucleon-nucleon potentials, combined with three-nucleon force, Coulomb interaction or carried out in a relativistic regime.
Low-Energy K- Nucleon/Multi-nucleon Interaction Studies by AMADEUS
M. Skurzok, M. Bazzi, G. Bellotti, A. M. Bragadireanu, D. Bosnar, A. Butt, M. Cargnelli, C. Curceanu, L. De Paolis, R. Del Grande, L. Fabbietti, C. Fiorini, F. Ghio, C. Guaraldo, R. Hayano, M. Iliescu, M. Iwasaki, P. Levi Sandri, J. Marton, M. Miliucci, P. Moskal, S. Okada, D. Pietreanu, K. Piscicchia, A. Ramos, A. Scordo, H. Shi, M. Silarski, D. L. Sirghi, F. Sirghi, A. Spallone, O. Vazquez Doce, E. Widmann, S. Wycech, J. Zmeskal
abstract
The AMADEUS collaboration aims to provide new experimental constraints to the K- N strong interaction in the regime of non-perturbative QCD, exploiting low-energy K- hadronic interactions with light nuclei (e.g. H, 4 He, 9 Be and 12 C). The low-momentum kaons ( p K -- 127 MeV/c) produced at the DAFNE collider are ideal to explore both stopped and in-flight K- nuclear captures. The KLOE detector is used as an active target, allowing to achieve excellent acceptance and resolutions for the data. In this work the results obtained from the study of Lambda pi- and Lambda p correlated production in the final state are presented.
Kaonic Deuterium Precision Measurement at DAFNE: The SIDDHARTA-2 Experiment
M. Miliucci, A. Amirkhani, A. Baniahmad, M. Bazzi, G. Bellotti, C. Berucci, D. Bosnar, M. Bragadireanu, M. Cargnelli, C. Curceanu, A. Dawood Butt, L. De Paolis, R. Del Grande, L. Fabbietti, C. Fiorini, F. Ghio, C. Guaraldo, M. Iliescu, M. Iwasaki, P. Levi Sandri, J. Marton, P. Moskal, S. Nied ? wiecki, z S. Okada, D. Pietreanu, K. Piscicchia, A. Scordo, H. Shi, M. Silarski, D. Sirghi, F. Sirghi, M. Skurzok, A. Spallone, H. Tatsuno, O. Vazquez Doce, E. Widmann and J. Zmeskal
abstract
Light kaonic atoms spectroscopy offers the unique opportunity to perform experiments equivalent to scattering at vanishing relative energies. This allows the determination of the antikaon-nucleus interaction at threshold, without the need of extrapolation to zero energy, as in the case of scattering experiments. In this framework, the SIDDHARTA-2 collaboration aims to perform the first measurement of kaonic deuterium transition to the fundamental level, which is mandatory to extract the isospin dependent antikaon-nucleon scattering lengths. The experiment will be carried out at the DA?NE collider of LNF-INFN in 2019-2020.
Search for the exotic nuclear matter with WASA-at-COSY
P. Moskal
abstract
Potential for biomedical applications of Positron Annihilation Lifetime Spectroscopy (PALS)
E. Kubicz for the J-PET collaboration
abstract
Positron Annihilation Lifetime Spectroscopy (PALS) allows examining structure of materials in nano and sub-nanometer
scale. This technique is based on the lifetime and intensity of ortho-positronium atoms in free volumes of given structures. It is
mostly used for studies in material sciences, but it can also be used for in vivo imaging of the cell morphology as proposed in [1],
[2]. Cancer cells are characterized by an altered macro structure in comparison to normal cells, thus the main objective of these
studies is to compare if these differences can be detected on sub-nanometer level with PALS technique. First studies on standard
PAL spectrometers conducted by Jean [3],[4] and J-PET collaboration [5], [6], give promising results showing differences between
normal and cancer tissues.
This perspective will allow for simultaneous determination of early and advanced stages of carcinogenesis, by observing
changes in biomechanical parameters between normal and tumour cells, and standard PET examination, which can be performed
with the Jagiellonian Positron Emission Tomograph (J-PET), a multi-purpose detector used for investigations with positronium
atoms in life-sciences as well as for development of medical diagnostics. Results of first PALS measurement of cardiac myxoma,
with J-PET detector is presented in this paper. Obtained o-Ps lifetime for tumor tissue is equal to 2.03(01)[ns] and its intensity
25.7(1)%.
Studies of the polarization of gamma photons originating from the decay of positronium atoms
S. Sharma, N. Krawczyk and J. Raj for the J-PET collaboration
abstract
The precise measurements of the Compton scatterings of photons originating from the decay of positronium atoms can reveal information about their polarizations. J-PET detector is constructed of 192 plastic scintillators and is unique to study the scattering correlations of the annihilation photons with an angular precision of several degrees. In this work, we present the first experimental evidence showing the feasibility of measuring the photons relative polarization using the J-PET detector.
Studies of J-PET detector to monitor range uncertainty in proton therapy
J. Baran, J. Gajewski, M. Pawlik-Niedzwiecka, P. Moskal, A. Ruciński on behalf of the J-PET Collaboration
abstract
2019 IEEE Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC), IEEE Xplore 2019 | DOI: 10.1109/NSS/MIC42101.2019.9059793
A problem of range uncertainty is currently one the most challenging in proton radiotherapy. To tackle that issue, the new, affordable, modular, lightweight, portable and reconfigurable technology of plastic scintillator based positron emission tomography was investigated. Monte Carlo simulation study was performed to evaluate the feasibility of the J-PET technology for proton beam range monitoring. Various configurations (single-layer, multi-layer, full ring, dual-head) were considered. 3D PET images were reconstructed using open-source CASToR software and the expected detector signal, as a function of detector acceptance and efficiency, was estimated. A relationship between the dose and activity profiles was investigated. Experimental validation of the presented results is currently under the preparation.
Status and Prospects of Discrete Symmetries Tests in Positronium Decays with the J-PET Detector
M. Silarski
abstract
Positronium is a unique laboratory to study fundamental symmetries in the Standard Model, reflection in space (P), reversal in time (T ), charge conjugation (C) and their combinations. The experimental limits on the C, CP and CPT symmetries violation in the decays of positronium are still several orders of magnitude higher than the expectations. The newly constructed Jagiellonian Positron Emission Tomograph (J-PET) was optimized for the registration of photons from the electron-positron annihilations. It enables tests of discrete symmetries in decays of positronium atoms via the determination of the expectation values of the discrete-symmetries-odd operators. In this article we present the capabilities of the J-PET detector in improving the current precision of discrete symmetries tests and report on the progress of analysis data from the first data-taking runs.
Kaonic atoms experiment at the DAFNE collider by SIDDHARTA/SIDDHARTA-2
M. Skurzok, A. Amirkhani, A. Baniahmad, M. Bazzi, D. Bosnar, M. Bragadireanu, M. Carminati, M. Cargnelli, A. Clozza, C. Curceanu, L. De Paolis, R. Del Grande, L. Fabbietti, C. Fiorini, C. Guaraldo, M. Iliescu, M. Iwasaki, P Levi Sandri, J. Marton, M. Miliucci, P Moskal, S. Niedzwiecki, S. Okada, D. Pietreanu, K. Piscicchia, A. Scordo, M. Silarski, D. Sirghi, F. Sirghi, A. Spallone, M. Tüchler, O. Vazquez Doce, E. Widmann and J. Zmeskal
abstract
The excellent quality kaon beam provided by the DAFNE collider of LNF-INFN (Italy)
together with SIDDHARTA/SIDDHARTA-2 new experimental techniques, as very precise
and fast-response X-ray detectors, allow to perform unprecedented measurements on
light kaonic atoms crucial for a deeper understanding of the low-energy quantum chro-
modynamics (QCD) in the strangeness sector. In this paper an overview of the main
results obtained by the SIDDHARTA collaboration, as well as the future plans related to
the SIDDHARTA-2 experiment, are discussed.
Latest Results in Kaon Physics on the KLOE Data and Status of Analysis of the KLOE-2 Data
E. Czerwiński
abstract
The KLOE-2 Collaboration concluded its data-taking at the DA?NE phi-factory of the Laboratori Nazionali di Frascati of INFN, collecting 5.5 fb-1 of data at the center of mass energy corresponding to the mass of the phi(1020). This sample together with the 2.5 fb-1 collected by the KLOE Collaboration until 2006 constitutes the largest sample in the world collected at the peak of the phi resonance. With the kaons produced in the decay phi->KSKL it is possible to perform very precise tests of the discrete symmetries T, CP, and CPT, and moreover the entanglement of the neutral kaons can be exploited to perform unique tests of quantum mechanics. Also large samples of eta mesons are produced in phi radiative decays, allowing to study the rare decays of this meson. KLOE-2 has also installed two tagging devices for electrons and positrons scattered in gg processes, with the main goal to study the single pi0 production. The search of new vector bosons in the hidden dark sector is also performed with the KLOE/KLOE-2 data. An information about the latest results with KLOE data on CPT test with charge asymmetry of KS semileptonic decays and a preliminary result on the CPT test in transitions is given.
Low-energy K- Hadronic Interactions with Light Nuclei by AMADEUS
M. Skurzok, M. Bazzi, G. Bellotti, A. M. Bragadireanu, D. Bosnar, M. Cargnelli, C. Curceanu, L. De Paolis, R. Del Grande, L. Fabbietti, C. Fiorini, F. Ghio, C. Guaraldo, R. Hayano, M. Iliescu, M. Iwasaki, P. Levi Sandri, J. Marton, M. Miliucci, P. Moskal, S. Okada, D. Pietreanu, K. Piscicchia, A. Ramos, A. Scordo, H. Shi, M. Silarski, D. L. Sirghi, F. Sirghi, A. Spallone, O. Vazquez Doce, E. Widmann, S. Wycech, J. Zmeskal
abstract
The AMADEUS collaboration aims to provide new experimental constraints to the K- N strong inter-
action in the regime of non-perturbative QCD, exploiting low-energy K- hadronic interactions with
light nuclei (e.g. H, 4He, 9Be and 12C). The low-momentum kaons (pK ~127 MeV/c) produced at
the DAFNE collider are ideal to explore both stopped and in-flight K- nuclear captures. The KLOE
detector is used as an active target, allowing to achieve excellent acceptance and resolutions for the
data. In this work the results obtained from the study of Lambda pi- and Lambda p correlated production in the
final state are presented.
Probing Strong Interaction with SIDDHARTA-2
J. Zmeskal, A. Scordo, A. Amirkhani, C. Amsler, A. Baniahmad, M. Bazzi, G. Bellotti, C. Berucci, D. Bosnar, M. Bragadireanu, M. Cargnelli, C. Curceanu, R. Del Grande, L. Fabbietti, C. Fiorini, F. Ghio, C. Guaraldo, M. Iliescu, M. Iwasaki, P. Levi Sandri, J. Marton, M. Miliucci, P. Moskal, D. Pietreanu, K. Piscicchia, A. Scordo, H. Shi, M. Silarski, D. L. Sirghi, F. Sirghi, M. Skurzok, A. Spallone, M. Tuechler, O. Vazquez Doce, E. Widmann
abstract
The antikaon-nucleon interaction close to threshold provides crucial information on the
interplay between spontaneous and explicit chiral symmetry breaking in low-energy QCD
involving strangeness. The unique feature of DAFNE, namely the production of low-energy
kaons, has led to a series of successfully conducted experiments with light kaonic atoms like
SIDDHARTA, where the most precise value for the antikaon-proton scattering length was
determined. Kaonic deuterium X-ray spectroscopy is still missing and with SIDDHARTA-2 the
ground state 1s-level shift and width should be measured with a precision of 30 eV and 75 eV,
respectively.
Hazardous Substance Detection in Water Environments using Neutron Beams: the SABAT Project
M. Silarski
abstract
The ever-increasing risk of terrorist attacks is a stimulus for seeking new, more effective danger detection methods. The article describes new methods of detecting hazardous materials based on the interaction between neutrons and matter. The status of the design of the device for detecting hazardous materials in water environments based on these methods, currently in development at the Jagiellonian University (Kraków, Poland), will be presented as well.
Kaonic atoms measurements at the DAFNE Collider
D. Sirghi, A. Amirkhani, A. Baniahmad, M. Bazzi, G. Bellotti, C. Berucci, D. Bosnar, M. Bragadireanu, M. Cargnelli, C. Curceanu, L. Fabbietti, C. Fiorini, F. Ghio, C. Guaraldo, M. Iliescu, M. Iwasaki, J. Martona, M. Miliucci, P. Moskal, S. Niedzwiecki, S. Okada, D. Pietreanu, K. Piscicchia, A. Scordo, H. Shi, M. Silarski, F. Sirghi, M. Skurzok, A. Spallone, H. Tatsuno, E. Widmann, J. Zmeskal
abstract
The DAFNE electron-positron collider of the Laboratori Nazionali di Frascati of INFN is a worldwide unique low-energy kaon source, which is being used to produce and to study kaonic atoms by the SIDDHARTA collaboration. The X-ray measurements of kaonic atoms play an important role for understanding the low-energy QCD in the strangeness sector. Significant achievements have been obtained by the SIDDHARTA experiment, among which: the most precise kaonic hydrogen measurement of the 1s level shift and width induced by the presence of the strong interaction; an upper limit of the X-ray yield for kaonic deuterium K-series; the accurate measurement of the 2p level shift and width of kaonic helium-4 and kaonic helium-3; yields of various light kaonic atoms transitions. Using the experience gained with SIDDHARTA experiment, the first kaonic deuterium measurement is in preparation in the framework of the SIDDHARTA-2 experiment with the goal to determine the antikaon-nucleon isospin dependent scattering lengths, which is possible only by combining the K-p and the upcoming K-d results. An overview of the experimental results of SIDDHARTA and an outlook to SIDDHARTA-2 experiments are given in this paper.
Towards total-body modular PET for positronium and quantum entanglement imaging
P. Moskal
abstract
The purpose of the reported research is (i) the elaboration of the new imaging method based on the in-vivo measurement of properties of positronium produced inside patient during positron emission tomography, and determination of correlations between properties of positronium inside the cancer tissues and histopathological characteristics of cancers, as well as (ii) exploration of possibilities of the determination of the linear polarization of annihilation photons and development of novel prognostic indicators for cancer diagnostics based on the quantum information from (multipartite) entanglement of photons originating from the positronium decay.During PET diagnosis positronium may be trapped inside free volumes between and within molecules of the examined patient. Currently, in the PET technique, the phenomenon of positronium production is neither recorded nor used for imaging. Yet in about 40% cases, the electron-positron annihilation proceeds in the tissue via creation of positronium. The properties of positronium (such as e.g. mean lifetime or ratio of decay rates into two and three photons) depend on the size of the free volumes between atoms and there are indications that they are correlated with the stage of the development of metabolic disorders of the human tissues. Therefore, an image of properties of positronium formed inside the human body may deliver new information complementary to SUV index and useful for the diagnosis.Moreover, recent theoretical studies have proven that the entanglement in the three-photon state from the decay of ortho-positronium survives surprisingly also for mixed scenarios expected in human tissues. Hence, detecting entanglement of photons originating from positronium may enable the extraction of quantum properties of the surrounding tissue environment.We discuss (i) results of the feasibility studies of the positronium mean-lifetime image reconstruction with the total-body PET scanner from plastic scintillators, as well as (ii) results of pilot studies of the mean lifetime of positronium in the healthy and tumorous tissues operated from the patients. Performed experiments show that properties of positronium atoms in uterine tissues operated from human patients reveals meaningful differences between healthy and tumorous tissues. We also discuss results of the feasibility studies of the polarization of annihilation photons with the J-PET tomograph in which annihilation photons interact predominantly via Compton scattering. Registration of both primary and scattered photons enables to determinate the linear polarization of the primary photon on the event by event basis and hence enables to witness the entanglement of annihilation photons in polarization based on Mutually Unbiased Bases. The performed simulations indicate that in the future with the total-body PET and improved time resolution it shall be feasible to reconstruct images of positronium properties in-vivo during the routine PET diagnosis.
Plastic scintillator based PET detector technique for proton therapy range monitoring: A Monte Carlo study
A. Rucinski, J. Baran, M. Garbacz, M. Pawlik-Niedzwiecka, P. Moskal
abstract
Currently a positron emission tomography (PET) based on novel, cutting-edge technology is developed by the Jagiellonian-PET (J-PET) collaboration. In this contribution, the principle of plastic scintillator based detector system, J-PET and the investigation of its feasibility for proton beam therapy range monitoring will be presented. Results of Monte Carlo simulation studies aiming at the characterization of secondary radiation induced by a proton beam in a PMMA phantom and detected by the J-PET scanner will be shown. Accounting for detector acceptance and PET-gamma detection efficiency in the plastics the diagnostic J-PET scanner can acquire 1.7×10?5 PET gammas per primary proton. The J-PET detector configurations and signal acquisition during and after the therapy is discussed.
Investigation of the Mechanism of Proton Induced Spallation Reactions
U. Singh, I. Ciepał, B. Kamys, P. Lasko, J. Łukasik, A. Magiera, P. Pawłowski, K. Pysz, Z. Rudy, S.K. Sharma
abstract
The mechanism of proton-nucleus interactions at GeV energies is still not well understood. The agreement between data and model predictions deteriorates with increasing ejectile energy and for the forward angles. This indicates the presence of preequilibrium processes which are not taken into consideration by present theoretical models. New experimental data are needed to put constraints to any new model of the reaction mechanism. The measurements are planned to be done to study proton-induced reactions at energies in the range from 70 to 230 MeV.
Kaonic Atoms Measurement at DAFNE: SIDDHARTA and SIDDHARTA-2
L. De Paolis, D. Sirghi, A. Amirkhani, A. Baniahmad, M. Bazzi, G. Bellotti, C. Berucci, D. Bosnar, M. Bragadireanu, M. Cargnelli, C. Curceanu, A. Dawood Butt, R. Del Grande, L. Fabbietti, C. Fiorini, F. Ghio, C. Guaraldo, M. Iliescu, M. Iwasaki, P. Levi Sandri, J. Marton, M. Miliucci, P. Moskal, S. Niedźwiecki, S. Okada, D. Pietreanu, K. Piscicchia, H. Shi, M. Silarski, F. Sirghi, M. Skurzok, A. Spallone, H. Tatsuno, O. Vazquez Doce, E. Widmann and J. Zmeskal
abstract
Light kaonic atoms studies provide the unique opportunity to perform experiments equivalent to scattering at threshold, being their atomic binding energies in the keV range. High precision atomic X-rays spectroscopy ensures that the energy shift and broadening of the lowest-lying states of the kaonic atoms, induced by the strong interaction between the kaon and nucleus, can be detected. Kaonic hydrogen and kaonic deuterium are the lightest atomic systems and their study deliver the isospin-dependent kaon-nucleon scattering lengths. The SIDDHARTA collaboration was able to perform the most precise kaonic hydrogen measurement to date, together with an exploratory measurement of kaonic deuterium. The measurement of the kaonic deuterium will be realized in the near future by a major upgrade of SIDDHARTA: SIDDHARTA-2. In this paper an overview of the main results obtained by SIDDHARTA together with the future plans are presented.
Low energy antikaon-nucleon/nuclei interaction studies by AMADEUS
K. Piscicchia, M. Bazzi, G. Belloti, A. M. Bragadireanu, D. Bosnar, A. D. Butt, M. Cargnelli, C. Curceanu, R. Del Grande, L. De Paolis, L. Fabbietti, C. Fiorini, F. Ghio, C. Guaraldo, R. S. Hayano, M. Iliescu, M. Iwasaki, P. Levi Sandri, J. Marton, M. Miliucci, P. Moskal, S. Okada, A. Ramos, A. Scordo, M. Silarski, D. L. Sirghi, F. Sirghi, M. Skurzok, A. Spallone, O. Vazquez Doce, E. Widmann, S. Wycech, J. Zmeskal
abstract
The AMADEUS experiment at the DAFNE collider of LNF-INFN deals with the investigation of the at-rest, or low-momentum, K-interactions in light nuclear targets, with the aim to constrain the low energy QCD models in the strangeness sector. The 0 step of the experiment consisted in the reanalysis of the 2004/2005 KLOE data, exploiting K-absorptions in H, 4He, 9Be and 12C, leading to the first invariant mass spectroscopic study with very low momentum (about 100 MeV) in-flight K- captures. With AMADEUS step 1 a dedicated pure Carbon target was implemented in the central region of the KLOE detector, providing a high statistic sample of pure at-rest K- nuclear interaction. The first measurement of the non-resonant transition amplitude |A K- n->Lambda pi- | at sqrt(s)=33 MeV below the K?N threshold is presented, in relation with the Lambda(1405) properties studies. The analysis procedure adopted in the search for K-multi-nucleon absorption cross sections and Branching Ratios will be also described.
Tests of discrete symmetries in positronium decays with the J-PET detector
M. Silarski
abstract
As a relatively simple and purely leptonic state positronium consti-tutes a unique system to study discrete symmetries with precision limited onlyby the effects due to the weak interaction and photon-photon scattering. Theexperimental tests in the positronium decays were performed only on theC,CPandCPTsymmetries with sensitivity much smaller than the predictions whichopens a large window to search for phenomena beyond the Standard Model. Inthis article we present capability of the J-PET detector to improve the current precision of discrete symmetries tests in the decays of positronium atom.
Plastic-scintillator based PET detector for proton beam therapy range monitoring: preliminary study
A. Rucinski, J. Baran, M. Garbacz, M. Pawlik-Niedzwiecka, P. Moskal
abstract
The new ADAM?s tool demonstrates suitable performances to test, in realistic patient-like conditions, tracking systems based on soft tissue detection.
Low Energy Antikaon-nucleon/nuclei interaction studies by AMADEUS
K. Piscicchia, M. Bazzi, G. Belloti, A. M. Bragadireanu, D. Bosnar, A. D. Butt, M. Cargnelli, C. Curceanu, R. Del Grande, L. De Paolis, L. Fabbietti, C. Fiorini, F. Ghio, C. Guaraldo, R. S. Hayano, M. Iliescu, M. Iwasaki, P. Levi Sandri, J. Marton, M. Miliucci, P. Moskal, S. Okada, A. Ramos, A. Scordo, M. Silarski, D. L. Sirghi, F. Sirghi, M. Skurzok, A. Spallone, O. Vazquez Doce, E. Widmann, S. Wycech and J. Zmeskal
abstract
The AMADEUS experiment at the DAFNE collider of LNF-INFN deals with the investigation of the at-rest, or low-momentum, K- interactions in light nuclear targets, with the aim to constrain the low energy QCD models in the strangeness sector. The 0 step of the experiment consisted in the reanalysis of the 2004/2005 KLOE data, exploiting K- absorptions in H, 4He, 9Be and 12C, leading to the first invariant mass spectroscopic study with very low momentum (about 100 MeV) in-flight K- captures. With AMADEUS step 1 a dedicated pure Carbon target was implemented in the central region of the KLOE detector, providing a high statistic sample of pure at-rest K- nuclear interaction. The first measurement of the non-resonant transition amplitude at below the K?N threshold is presented, in relation with the Lambda(1405) properties studies. The analysis procedure adopted in the serarch for K- multi-nucleon absorption cross sections and Branching Ratios will be also described.
Lambdap correlated production from low energy K- 12C interactions by AMADEUS
R. Del Grande, M. Bazzi, G. Belloti, A. M. Bragadireanu, D. Bosnar, A. D. Butt, M. Cargnelli, C. Curceanu, L. De Paolis, L. Fabbietti, C. Fiorini, F. Ghio, C. Guaraldo, R. S. Hayano, M. Iliescu, M. Iwasaki, P. Levi Sandri, J. Marton, M. Miliucci, P. Moskal, S. Okada, D. Pietreanu, K. Piscicchia, A. Ramos, A. Scordo, H. Shi, M. Silarski, D. L. Sirghi, F. Sirghi, M. Skurzok, A. Spallone, O. Vazquez Doce, E. Widmann, S. Wycech and J. Zmeskal
abstract
The main steps for the analysis of the Lambdap correlated production in low-energy K- captures on Carbon nuclei, performed by the AMADEUS collaboration, are presented. The goal is to perform the first comprehensive study of the K- absorption on two, three and four nucleons, exploiting the lowmomentum K-s (pK ~ 127 MeV/c) produced at the DAFNE collider, and to measure the low-energy cross sections and branching ratios of the K- multinucleon absorption processes in both the Lambdap and Sigma0p channels. An integrated luminosity of 1.74 fb-1 collected during the KLOE 2004/2005 data campaign is analysed by reconstructing the Lambdap final state.
Spectroscopy of kaonic atoms at DAFNE and J-PARC
J. Marton, A. Amirkhan, A. Baniahmad, M. Bazzi, G. Bellotti, C. Berucci, D. Bosnar, M. Bragadireanu, M. Cargnelli, C. Curceanu, A. Dawood Butt, R. Del Grande, L. Fabbietti, C. Fiorini, F. Ghio, C. Guaraldo, M. Iliescu, M. Iwasaki, P. Levi Sandri, M. Miliucci, P. Moskal, S. Niedźwiecki, S. Okada, D. Pietreanu, K. Piscicchia, H. Shi, M. Silarski, D. Sirghi, F. Sirghi, M. Skurzok, A. Spallone, H. Tatsuno, O. Vazquez Doce, E. Widmann and J. Zmeskal
abstract
The interaction of antikaons (K-) with nucleons and nuclei in the low-energy regime represents a very active research field in hadron physics. A unique and rather direct experimental access to the antikaon-nucleon scattering lengths is provided by precision X-ray spectroscopy of transitions in low-lying states in the lightest kaonic atoms (i.e. kaonic hydrogen and deuterium). In the SIDDHARTA experiment at the electron-positron collider DAFNE of LNFINFN we measured the most precise values of the strong interaction observables in conic hydrogen. The strong interaction on the 1s ground state of the electromagnetically bound K-p atom causes an energy shift and broadening of the 1s state. SIDDHARTA will extend the spectroscopy to kaonic deuterium to get access to the antikaon-neutron interaction and thus the isospin dependent scattering lengths. At J-PARC a kaon beam is used in a complementary experiment with a different setup for spectroscopy of kaonic deuterium atoms. The talk will give an overview of the of the upcoming experiments SIDDHARTA and the complementary experiment at J-PARC.Furthermore, the implications of the experiments for the theory of low-energy strong interaction with strangeness will be discussed.
Search for the eta-mesic bound states with the WASA-at-COSY detector
M. Skurzok
abstract
The experiments dedicated to the search for eta-mesic Helium were performed with high statistics using WASA detection setups installed at the COSY accelerator in the Research Center Juelich. The search for the eta-mesic bound states is conducted via the measurement of the excitation function for selected decay channels of the He-eta systems using unique ramped beam technique. This report presents recent status of the data analysis.
Search for eta-mesic 3He in non-mesonic final state
O. Rundel, M. Skurzok and A. Khreptak
abstract
The experiment on searching for eta-mesic 3He nucleus was performed in May 2014 at COSY accelerator in Juelich by WASA-at-COSY Collaboration. The measurements were carried out using ramped beam technique which allows for the slow and continuous beam momentum change near the threshold of eta meson creation. The luminosity was obtained based on pd -> 3He? reaction and quasielastic proton-proton scattering. The bound state of eta-meson and 3He nucleus is searched for in pd -> 3He2gamma and pd -> 3He6gamma channels. The analysis is still in progress and the estimated upper limit value is on the level of few nanobarns.
Luminosity determination for the proton-deutron reactions using quasi-free reactions with WASA-at-COSY facility
A. Khreptak, O. Rundel and M. Skurzok
abstract
The scientific aim of our research is experimental confirmation of the existence of mesic-nucleus: a new exotic kind of nuclear matter consisting of nucleons and mesons. In this report we present the method of luminosity determination for experiment performed atWASA-at-COSY detector dedicated to search for 3He-eta bound state. This method is based on analysis of quasi-free reaction.
Near threshold kaon-kaon interaction in the reactions e+e-->K+K-gamma and e+e-->K0bar{K0}gamma
L. Leśniak, F. Sobczuk, M. Silarski and F. Morawski
abstract
Strong interactions between pairs of the K+K- and K0bar{K0} mesons can be studied in radiative decays of phi(1020) mesons. We present a theoretical model of the reactions e+e-->K+K-gamma and e+e-->K0bar{K0}gamma. The K+K- and K0bar{K0} effective mass dependence of the differential cross sectionsis derived. The total cross sections and the branching fractions for the two radiative phi decays are calculated.
Study of the time reversal symmetry in the decay of ortho-Positronium atoms using the J-PET detector
J. Raj, M. Silarski
abstract
The Jagiellonian Positron Emission Tomograph (J-PET) is a novel device based on organic scintillators being developed at Jagiellonian University in Kraków, Poland. J-PET is an axially symmetric and high acceptance scanner that can be used as a multi-purpose detector system. It is well suited to pursue tests of discrete symmetries in decays of positronium in addition to medical imaging. J-PET enables measurement of both momenta and polarization vectors of annihilation photons. The latter is a unique feature of the J-PET detector which allows study of the time reversal symmetry violation operator constructed solely from the annihilation photons momenta before and after scattering within the detector.
Time Over Threshold as a measure of energy response of plastic scintillators used in the J-PET detector
S. Sharma
abstract
The Jagiellonian Positron Emission Tomograph (J-PET) is a multi-purpose detector being developed to provide an economical alternative of com-mercially available PETs as well as to perform the tests on the discrete sym-metries and entanglement. It is composed of 192 plastic scintillators axiallyarranged in three cylindrical layers. In the framework of J-PET detector, Time-Over-Threshold (TOT) approach is adopted for the signal readouts in order toutilize the excellent time resolution of the plastic scintillators. In this paper, wepresent a method elaborated for establishing a relation between TOT and energyloss.
The tests of CP and CPT symmetry using the J-PET detector
M. Mohammed, A Gajos
abstract
Symmetries under the parity transformation (P), charge-conjugation (C) and time reversal (T) are of fundamental importance in nuclear and elementary particle physics. Studies of the observables violating the combined CP symmetry constitute precise tests of the Standard Model. However, CP violation was observed to date only for systems involving quarks, raising the importance of searches its manifestations e.g. in purely leptonic systems. The 3? decay of spin-aligned ortho-positronium atoms (o-Ps) can be used to test CP invariance in such a purely leptonic system. The Jagiellonian Positron Emission Tomograph (J-PET) detection system enables experimental tests of CP and CPT through measurement of the expectation values of angular correlation operators odd under these transformations and constructed from (i) spin vector of the ortho-positronium atom, (ii) co-planar momentum vectors of photons originating from the decay of the positronium atom, and (iii) linear polarization direction of annihilation photons. Precise experimental symmetry tests with J-PET are possible thanks to a dedicated reconstruction technique of 3? ortho-positronium decays and a positronium production chamber including a highly porous aerogel target, whose setup allows for determining the orthopositronium spin polarization without the use of an external magnetic field.
Discrete symmetries studies at KLOE-2
D. Kisielewska
abstract
The KLOE and KLOE-2 experiments at the Laboratori Nazionali di Frascati (Italy) collected almost 8 fb ?1 of integrated luminosity at the energy equal to the mass of ? meson. The excellent time resolution of the electromagnetic calorimeter and the very good accuracy on both momentum and vertex reconstruction of the tracking system allow to study discrete symmetries to
the utmost precision as well as light meson spectroscopy, dark forces searches, hadronic cross-section measurements and studies of ??-physics. CPT symmetry test with the lepton charge asymmetry measured in K S semileptonic decays with 1.7 fb ?1 of KLOE data, tests of time reversal and CPT in transitions in ? ? K S K L ? ?e?, 3? 0 (2? 0 ) decays with newly acquired data with the KLOE-2 detector will be presented and discussed.
Drift chamber calibration and particle identification in the P-349 experiment
D. Alfs, A. Asaturyan, M. Carmignotto, M. Diermaier, W. Eyrich, B. Głowacz, D. Grzonka, F. Hauenstein, T. Horn, K. Kilian, D. Lersch, S. Malbrunot-Ettenauer, A. Mkrtchyan, H. Mkrtchyan, P. Moskal, P. Nadel-Turonski, W. Oelert, J. Ritman, T. Sefzick, V. Tadevosyan, E. Widmann, M. Wolke, S. Zhamkochyan, M. Zieliński, A. Zink and J. Zmeskal
abstract
The goal of the P-349 experiment is to test whether 3.5 GeV/c antiprotons produced in high-energy proton-proton collisions are polarized in view of the preparation of a polarized antiproton beam. In this article, we present the details of the ongoing analysis focused on the drift chambers calibration and particle identification with DIRC.
Polarization analysis of antiprotons produced in pA collisions
D. Alfs, A. Asaturyan, M. Carmignotto, M. Diermaier, W. Eyrich, B. Głowacz, D. Grzonka, F. Hauenstein, T. Horn, K. Kilian, D. Lersch, S. Malbrunot-Ettenauer, A. Mkrtchyan, H. Mkrtchyan, P. Moskal, P. Nadel-Turonski, W. Oelert, J. Ritman, T. Sefzick, V. Tadevosyan, E. Widmann, M. Wolke, S. Zhamkochyan, M. Zieliński, A. Zink and J. Zmeskal
abstract
A quite simple procedure for the generation of a polarized antiproton beam could be worked out if antiprotons are produced with some polarization. In order to investigate this possibility measurements of the polarization of produced antiprotons have been started at a CERN/PS test beam. The polarization will be determined from the asymmetry of the elastic antiproton scattering at a liquid hydrogen target in the CNI region for which the analyzing power is well known. The data are under analysis and an additional measurement is done in 2018. Details on the experiment and the ongoing data analysis will be given.
A charged particle veto detector for kaonic deuterium measurements at DAFNE
M. Tüchler, J. Zmeskal, A. Amirkhani, M. Bazzi, G. Bellotti, C. Berucci, D. Bosnar, A.M. Bragadireanu, M. Cargnelli, C. Curceanu, A. Dawood Butt, R. Del Grande, L. De Paolis, L. Fabbietti, C. Fiorini, F. Ghio, C. Guaraldo, R.S. Hayano, M. Iliescu, M. Iwasaki, P.Levi Sandri, J. Marton, M. Miliucci, P. Moskal, D. Pietreanu, K. Piscicchia, A. Scordo, H. Shi, M. Silarski, D. Sirghi, F. Sirghi, M. Skurzok, A. Spallone, O. Vazquez Doce, E. Widmann
abstract
The antikaon-nucleon interaction close to threshold provides crucial information on the interplay between spontaneous and explicit chiral symmetry breaking in low-energy QCD. In this context, the importance of kaonic deuterium x-ray spectroscopy has been well recognized, but no experimental results have yet been obtained due to the difficulty of the measurement. To measure the shift and width of the kaonic deuterium 1s state with an accuracy of 30 eV and 75 eV, respectively, an apparatus is under construction at the Laboratori Nazionali di Frascati. A detailed Monte Carlo simulation has shown that an increase of the signal to background ratio by a factor of ten will be required compared to the successfully performed kaonic hydrogen measurement (SIDDHARTA). Three pillars are essential for the newly developed experimental apparatus: a large area x-ray detector system (consisting of Silicon Drift Detectors), a lightweight cryogenic target system and a veto system, consisting of an outer veto detector (Veto-1) for active shielding and an inner veto detector (Veto-2) for charged particle suppression. For both veto systems, an excellent time resolution is required to distinguish kaons stopping in gas from direct kaon stops in the entrance window or side wall of the target. First test measurements on the Veto-2 system were performed. An average time resolution of (54 +- 2) ps and detection efficiencies of ~ 99 % were achieved.
The kaonic atoms research program at DAFNE: overview and perspectives
C. Curceanu, A. Amirkhani, A Baniahmad, M. Bazzi, G. Bellotti, C. Berucci, D. Bosnar, A.M. Bragadireanu, M. Cargnelli, A. Dawood Butt, R. Del Grande, L. Fabbietti, C. Fiorini, F. Ghio, C. Guaraldo, M. Iliescu, M. Iwasaki, P.Levi Sandri, J. Marton, M. Miliucci, P. Moskal, S. Niedzwiecki, S. Okada, D. Pietreanu, K. Piscicchia, H. Shi, M. Silarski, D. Sirghi, F. Sirghi, M. Skurzok, A. Spallone, H. Tatsuno, O. Vazquez Doce, E. Widmann, J. Zmeskal
abstract
The interaction of antikaons with nucleons and nuclei in the low-energy regime represents an active research field in hadron physics with still many important open questions. The investigation of light kaonic atoms is, in this context, a unique tool to obtain precise information on this interaction. The energy shift and broadening of the lowest-lying states of such atoms, induced by the kaon-nucleus strong interaction, can be determined with high precision from atomic X-ray spectroscopy. This experimental method provides unique information to understand the low energy kaon-nucleus interaction at threshold. The lightest atomic systems, kaonic hydrogen and kaonic deuterium, deliver the isospin-dependent kaon-nucleon scattering lengths. The most precise kaonic hydrogen measurement to date, together with an exploratory measurement of kaonic deuterium, were carried out by the SIDDHARTA collaboration at the DAFNE electron-positron collider of LNF-INFN, by combining the excellent quality kaon beam delivered by the collider with new experimental techniques, as fast and precise X-ray detectors: Silicon Drift Detectors. The measurement of kaonic deuterium will be realized in the near future by SIDDHARTA-2, a major upgrade of SIDDHARTA. In this paper an overview of the main results obtained by SIDDHARTA together with the future plans, are given.
A New Silicon Drift Detector System for Kaonic Atom Measurements
C. Trippl, ..., R. Del Grande, ..., P. Moskal, ...
abstract
The kaonic deuterium measurement at J-PARC and DAFNE will provide a piece of information still missing to the antikaon-nucleon interaction close to threshold, providing valuable information to answer one of the most fundamental problems in hadron physics today - to the yet unsolved puzzle of how the hadron mass is generated. For this a new X-ray detector system has been developed to measure the shift and width of the 2p -> 1s transition of kaonic deuterium with a precision of 60 eV and 140 eV, respectively.
Investigation of the mechanisms of spallation reactions
U. Singh
abstract
CP, T and CPT tests with neutral kaons at KLOE-2
M. Silarski
abstract
We report on the recent results on CP, T and CPT tests in the neutral kaon sector obtained with the KLOE dataset. Search for the CP-violating decay KS?3?0 is described. We present also recent measurement of the charge asymmetry for the KS??e? decay and preliminary results of direct test of T and CPT in neutral kaon transitions. Prospects of further improvement of these tests with KLOE-2 dataset are also given.
Implementation of the conjugate gradient algorithm on FPGA devices
G. Korcyl, P. Korcyl
abstract
Results of porting parts of the Lattice Quantum Chromodynamics code to modern FPGA devices are presented. A single-node, double precision implementation of the Conjugate Gradient algorithm is used to invert numerically the Dirac-Wilson operator on a 4-dimensional grid on a Xilinx Zynq evaluation board. The code is divided into two software/hardware parts in such a way that the entire multiplication by the Dirac operator is performed in programmable logic, and the rest of the algorithm runs on the ARM cores. Optimized data blocks are used to efficiently use data movement infrastructure allowing to reach intervals of 1 clock cycle. We show that the FPGA implementation can offer a comparable performance compared to that obtained using Intel Xeon Phi KNL.
Low Energy Antikaon-Nucleon/Nuclei Interaction Studies by AMADEUS
K. Piscicchia, M. Cargnelli, C. Curceanu, R. Del Grande, L. Fabbietti, C. Guaraldo, J. Marton, P. Moskal, A. Scordo, M. Silarski, D. L. Sirghi, M. Skurzok, I. Tucakovic, O. Vazquez Doce, E. Widmann, S. Wycech, J. Zmeskal
abstract
The AMADEUS experiment at the DAFNE collider of LNF-INFN deals with the investigation of the at-rest, or low-momentum, K- interactions in light nuclear targets, with the aim to constrain the low energy QCD models in the strangeness sector. The 0 step of the experiment consisted in the reanalysis of the 2004/2005 KLOE data, exploiting K- absorptions in H, 4He, 9Be and 12C, leading to the first invariant mass spectroscopic study with very low momentum (about 100 MeV) in-flight K- captures. With AMADEUS step 1 a dedicated pure Carbon target was implemented in the central region of the KLOE detector, providing a high statistic sample of pure at-rest K- nuclear interaction. The first measurement of the non-resonant transition amplitude |AK-n->Lambda pi-| at ?s = 33 MeV below the KN threshold is presented, in relation with the Lambda(1405) properties studies.
The kaonic atoms research program at DAFNE: from SIDDHARTA to SIDDHARTA-2
A. Scordo, A. Amirkhani, M. Bazzi, G. Bellotti, C. Berucci, D. Bosnar, A.M. Bragadireanu, M. Cargnelli, C. Curceanu, A. Daewood Butt, R. Del Grande, L. Fabbietti, C. Fiorini, F. Ghio, C. Guaraldo, R.S. Hayano, M. Iliescu, M. Iwasaki, P. Levi Sandri, J. Marton, M. Miliucci, P. Moskal, D. Pietreanu, K. Piscicchia, H. Shi, M. Silarski, D. Sirghi, F. Sirghi, M. Skurzok, A. Spallone, H. Tatsuno, O. Vazquez Doce, E. Widmann, J. Zmeskal
abstract
The interaction of antikaons with nucleons and nuclei in the low-energy regime represents an active research field in hadron physics with still many important open questions. The investigation of light kaonic atoms, in which one electron is replaced by a negatively charged kaon, is a unique tool to provide precise information on this interaction; the energy shift and the broadening of the low-lying states of such atoms, induced by the kaon-nucleus hadronic interaction, can be determined with high precision from the atomic X-ray spectroscopy, and this experimental method provides unique information to understand the low energy kaon-nucleus interaction at the production threshold. The lightest atomic systems, like the kaonic hydrogen and the kaonic deuterium deliver, in a model-independent way, the isospin-dependent kaon-nucleon scattering lengths. The most precise kaonic hydrogen measurement to-date, together with an exploratory measurement of kaonic deuterium, were carried out in 2009 by the SIDDHARTA collaboration at the DA?NE electron-positron collider of LNF-INFN, combining the excellent quality kaon beam delivered by the collider with new experimental techniques, as fast and very precise X-ray detectors, like the Silicon Drift Detectors. The SIDDHARTA results triggered new theoretical work, which achieved major progress in the understanding of the low-energy strong interaction with strangeness reflected by the antikaon-nucleon scattering lengths calculated with the antikaon-proton amplitudes constrained by the SIDDHARTA data. The most important open question is the experimental determination of the hadronic energy shift and width of kaonic deuterium; presently, a major upgrade of the setup, SIDDHARTA-2, is being realized to reach this goal. In this paper, the results obtained in 2009 and the proposed SIDDHARTA-2 upgrades are presented.
Studies of low-energy K- nuclear interactions by AMADEUS
R. Del Grande, M. Bazzi, G. Belloti, A. M. Bragadireanu, D. Bosnar, A. D. Butt, M. Cargnelli, C. Curceanu, L. De Paolis, L. Fabbietti, C. Fiorini, F. Ghio, C. Guaraldo, R. S. Hayano, M. Iliescu, M. Iwasaki, P. Levi Sandri, J. Marton, M. Miliucci, P. Moskal, S. Okada, D. Pietreanu, K. Piscicchia, A. Scordo, H. Shi, M. Silarski, D. L. Sirghi, F. Sirghi, M. Skurzok, A. Spallone,O. Vazquez Doce, E. Widmann, S. Wycech, J. Zmeskal
abstract
The goal of the AMADEUS experiment is to shed light on unsolved fundamental issues in the non-perturbative strangeness QCD sector through the study of lowenergy K- hadronic interactions with light nuclear targets. The main open questions are the controversial nature of the Delta(1405) state, which is investigated in hyperon-pion correlation studies, and the possible existence of exotic antikaon multi-nucleon clusters, whose search in K- induced reactions is intimately related to the studies of the K- multi-nucleon absorption processes in hyperon-nucleon/nucleus channels. The DAFNE collider at the INFN-LNF provides unique monochromatic low-momentum kaons from the ? meson decay almost at-rest, suitable for the AMADEUS studies. The KLOE detector is exploited as an active target, in order to obtain excellent acceptance and resolution data for K- nuclear capture on H, 4He, 9Be and 12C, both at-rest and in-flight.
Low energy interaction studies of negative kaons in light nuclear targets by AMADEUS
K. Piscicchia, M. Bazzi, G. Belotti, A. M. Bragadireanu, D. Bosnar, A. D. Butt, M. Cargnelli, C. Curceanu, R. Del Grande, L. De Paolis, L. Fabbietti, C. Fiorini, F. Ghio, C. Guaraldo, R. S Hayano, M. Iliescu, M. Iwasaki, P. Levi Sandri, J. Marton, M. Miliucci, P. Moskal, S. Okada, D. Pietreanu, A. Scordo, M. Silarski, D. L. Sirghi, F. Sirghi, M. Skurzok, A. Spallone, O. Vazquez Doce, E. Widmann, S. Wycech, J. Zmeskal
abstract
The AMADEUS collaboration is performing experimental investigations in the sector of the low energy strangeness hadron physics by taking advantage of the DAFNE collider, which provides a unique source of monochromatic low-momentum kaons and exploiting the KLOE detector as an active target. The K- single and multi-nuclear absorption on H, 4He, 9Be and 12C, both at-rest and in-flight, are studied with the aim to determine the nature of the controversial Lambda(1405), the non-resonant hyperon pion formation amplitude below the K?N threshold, the yield and cross sections of K- multi-nucleon absorptions intimately connected to the antikaon multi-nucleon clusters properties and the K- scattering cross sections on light nuclear targets.
These studies have a strong impact on the non-perturbative strangeness QCD with implications ranging from nuclear physics to the equation of state of neutron stars.
Studies of discrete symmetries in decays of positronium atoms
E. Czerwiński, C. Curceanu, K. Dulski, A. Gajos, M. Gorgol, A. Heczko, B. C. Hiesmayr, B. Jasińska, D. Kisielewska, G. Korcyl, B. Korzeniak, P. Kowalski, T. Kozik, W. Krzemień, E. Kubicz, W. Migdał, M. Mohammed, S. Niedźwiecki, M. Pałka, M. Pawlik-Niedźwiecka, L. Raczyński, J. Raj, Z. Rudy, S. Sharma, S. Shivani, R. Y. Shopa, M. Silarski, M. Skurzok, W. Wiślicki, B. Zgardzińska, M. Zieliński and P. Moskal
abstract
A positronium - a bound state of electron and positron - is an eigenstate of parity and charge conjugation operators which decays into photons. It is a unique laboratory to study discrete symmetries whose precision is limited, in principle, by the effects due to the weak interactions expected at the level of 10?14 and photon-photon interactions expected at the level of 10-9.
The Jagiellonian Positron Emission Tomograph (J-PET) is a detector for medical imaging as well as for physics studies involving detection of electronpositron annihilation into photons. The physics case covers the areas of discrete symmetries studies and genuine multipartite entanglement. The J-PET detector has high angular and time resolution and allows for determination of spin of the positronium and the momenta and polarization vectors of annihilation quanta. In this article, we present the potential of the J-PET system for studies of discrete symmetries in decays of positronium atoms.
Luminosity determination for the proton-deuteron reaction using pd -> 3He eta channel with WASA-at-COSY detector
M. Skurzok, O. Rundel, A. Khreptak, P. Moskal
abstract
In this report one of the methods used for the luminosity determination for the experiment performed by WASA Collaboration to search for 3He-eta mesic nuclei is presented. The method is based on the analysis of pd -> 3He eta process.
Low-energy antikaon-nuclei interactions studies by AMADEUS: from QCD with strangeness to neutron stars
K. Piscicchia,..., R. Del Grande, ..., P. Moskal
abstract
The AMADEUS collaboration aims to provide unique quality results from K- hadronic interactions in light nuclear targets, in order to solve fundamental open questions in the non-perturbative strangeness QCD sector, like the controversial nature of the Lambda(1405) state, the yield of hyperon formation below threshold, the yield and shape of multi-nucleon K- absorption, processes which are intimately connected to the possible existence of exotic antikaon multi-nucleon clusters and to the role of strangeness in neutron stars. AMADEUS takes advantage of the DAFNE collider, which provides a unique source of monochromatic low-momentum kaons and exploits the KLOE detector as an active target, in order to obtain excellent acceptance and resolution data for K- nuclear capture on H, 4He, 9Be and 12C, both at-rest and in-flight.
Search for Deeply Bound Kaonic Nuclear States with AMADEUS
M. Skurzok, M. Cargnelli, C. Curceanu, R. Del Grande, L. Fabbietti, C. Guaraldo, J. Marton, P. Moskal, K. Piscicchia, A. Scordo, M. Silarski, D. L. Sirghi, I. Tucakovic, O. Vazquez Doce, S. Wycech, E. Widmann, J. Zmeskal
abstract
We briefly report on the search for Deeply Bound Kaonic Nuclear States with AMADEUS in the Sigma0p channel following K- absorption on 12C and outline future perspectives for this work.
Studies of the diecrete symmetries in Nature
P. Moskal
abstract
We exist, so there must also be some sort of asymmetry between matter and antimatter. Otherwise, the whole matter and antimatter would long ago have turned into photons, ie light, as a result of mutual annihilation of particles and antiparticles. The explanation of this asymmetry, essentially identical with the explanation of the existence of matter in general, is one of the most interesting cognitive challenges of modern physics and cosmology.
Latest studies on the reaction e+ e- --> K + K- gamma
L. Leśniak, M. Silarski
abstract
Recent theoretical studies of the e+ e- -> K + K- gamma process are described. Three main reaction mechanisms are considered: the initial state radiation, the final state radiation and the strong interaction between the outgoing K+ K- mesons. The K+ K- effective mass distributions are derived for three different models which in past have been used for a description of the e+ e- -> pi+ pi- gamma data. Also the numerical results for the angular photon and kaon distributions are presented. A new model of the e+ e- -> M_1 M_2 gamma reactions is outlined which can serve for multichannel analyses of the radiative processes with a production of two pseudoscalar mesons M_1 and M_2.
Recent Results from WASA-at-COSY
H. Clement, P. Moskal, M. Skurzok
abstract
The detector system WASA-at-COSY has been operated at the Cooler Synchrotron COSY in the years from 2006 till 2015. In this article we report on recent results of the analyses of the meson production reactions in nucleon?nucleon, nucleon?deuteron, and deuteron?deuteron collisions with spin-polarized and unpolarized beams emphasizing the evidences for the existence of the dibaryon state in the proton-neutron system and the perspectives for the search of the eta-mesic helium.
J-PET: A novel TOF-PET detector based on plastic scintillators
Paweł Moskal, Dominika Alfs, Tomasz Bednarski, Piotr Białas, Catalina Curceanu, Eryk Czerwiński, Kamil Dulski, Aleksander Gajos, Bartosz Głowacz, Marek Gorgol, Beatrix Hiesmayr, Bożena Jasińska, Daria Kamińska, Grzegorz Korcyl, Paweł Kowalski, Tomasz Kozik, Wojciech Krzemień, Ewelina Kubicz, Muhsin Mohammed, Monika Pawlik-Niedźwiecka, Szymon Niedźwiecki, Marek Pałka, Lech Raczyźski, Zbigniew Rudy, Oleksandr Rundel, Neha Gupta Sharma, Michał Silarski, Jerzy Smyrski, Adam Strzelecki, Anna Wieczorek, Wojciech Wiślicki, Bożena Zgardzińska, Marcin Zieliński
abstract
Statistical Analysis of Time Resolution of the J-PET Scanner
L. Raczyński, W. Wiślicki, P. Kowalski, W. Krzemień, D. Alfs, T. Bednarski, P. Białas, C. Curceanu, E. Czerwiński, K. Dulski, A. Gajos, B. Głowacz, M. Gorgol, B. Hiesmayr, B. Jasińska, D. Kamińska, G. Korcyl, T. Kozik, N. Krawczyk, E. Kubicz, M. Mohammed, M. Pawlik-Niedźwiecka, S. Niedźwiecki, M. Pałka, Z. Rudy, O. Rundel, N. Gupta Sharma, M. Silarski, J. Smyrski, A. Strzelecki, A. Wieczorek, B. Zgardzińska, M. Zieliński, P. Moskal
abstract
Low-energy Antikaon-Nucleon Absorption Studies by AMADEUS
K. Piscicchia,..., R. Del Grande, ..., P. Moskal, ..., M. Silarski, ..., M. Skurzok, ...
abstract
The AMADEUS experiment investigates the low-energy kaon?nuclei hadronic interaction at the DA?NE collider at LNF-INFN. In particular, the study of hyperon resonances formation, following K--induced reactions in light nuclear targets, will be presented. The 0 step of the experiment consisted in the reanalysis of the 2004/2005 KLOE data, exploiting K- absorptions in H, 4He, 9Be and 12C, leading to the first invariant mass spectroscopic study with very low momentum (about 100 MeV) in-flight K- captures. With AMADEUS step 1, a dedicated pure carbon target was implemented in the central region of the KLOE detector, providing a high statistic sample of pure at-rest K nuclear interaction. The results obtained in the analyses of the hyperon?pion correlated events, searching for the resonant shapes of Y* states, will be described.
Discrete symmetries and QM studies with entangled neutral kaons at KLOE-2
A. Gajos
abstract
The long history of kaon physics results produced by KLOE is being continued at the upgraded KLOE-2 detector. Entangled neutral kaon pairs produced at DA?NE are a unique tool to probe discrete symmetries and QM basic principles at the utmost precision. The status of the newest ongoing analyses using the most refined analysis tools will be presented and discussed:(i) search for decoherence and CPT violation effects in the ? ? K(S)K(L) ? ? (+) ? (?) ? (+) ? (?) decay,(ii) test of CP and CPT symmetries in K(S) semileptonic decays,(iii) test of time reversal and CPT in transitions in ? ? K(S)K(L) ? ?e?, 3? (0), 2? decays,(iv) study of the K(S) ? ? (+) ? (?) ? (0) decay.
Probing Strong Interaction with Kaonic Atoms from DAFNE to J-PARC
J. Zmeskal, ...,P. Moskal, et al.
abstract
The study of the antikaon nucleon system at very low energies plays a key role to study strong interaction with strangeness, touching one of the fundamental problems in hadron physic today???the still unsolved question of how hadron masses are generated. Exotic atoms offer a unique possibility to determine s-wave kaon-nucleon scattering lengths at vanishing energy. At the DAFNE electron positron collider of Laboratori Nazionali di Frascati in the SIDDHARTA experiment kaonic atoms were formed with Z = 1 (K-p) and Z = 2 (K-He), which were measured with up to now unrivalled precision. This experiment is taking advantage of the low-energy charged kaons from phi-mesons decaying nearly at rest. Finally, using the experience gained with SIDDHARTA, a proposal to measure kaonic deuterium for the first time was submitted to J-PARC with the goal to determine the isospin dependent scattering lengths, which is only possible by combining the K-p and the upcoming K-d results.
Investigating the low-energy K- interactions in nuclear matter with AMADEUS
R. Del Grande, ...., P. Moskal, et al. (AMADEUS Collaboration)
abstract
The AMADEUS collaboration studies low-energy K- interactions with light nuclei in order to clarify some aspects related to the behaviour of hadrons containing strangeness in nuclear medium. One of the main topics is the quest about the possible formation of Kaonic Nuclear Clusters (KNC), which depends on the strength of the anti-kaons interaction with nucleons. In kaonic absorption experiments, the search for KNC is strictly connected with the measurement of the yields of the so-called multi-nucleon absorption processes. In this paper, the study of Sigma0p correlated production from K? absorption in 12C, using the KLOE 2004-2005 data set, is reported. The yield of the two nucleon absorption (2NA), when the produced Sigma0 and p particles are free from any final state interaction process, was measured for the first time. The contribution of a ppK- bound state was also tested. The best fit is obtained for a ppK? state with a binding energy of 45 MeV and a width of 30 MeV, but the statistical significance is at the level of 1? only.
Antikaon Interactions with Nucleons and Nuclei - AMADEUS At Dafne
J. Marton, ..., P. Moskal, ..., M. Skurzok
abstract
PoS INPC2016 (2017) 290
The aim of AMADEUS is to provide unprecedented experimental information on K- absorption
in light nuclear targets, to face major open problems in hadron nuclear physics in the strangeness sector, namely the nature of the L(1405), strongly related to the possible existence of kaonic nuclear clusters, kaons and hyperon scattering cross sections on nucleons and nuclei. These issues are fundamental for a better understanding of the non-perturbative QCD in the strangeness sector.
AMADEUS step 0 deals with the analysis of the 2004-2005 KLOE collected data. The interactions
of the negative kaons produced by the DAFNE collider (a unique source of monochromatic
low-momentum kaons) with the materials of the KLOE detector, used as active targets, provide
samples of K- absorptions on H, 4He, 9Be and 12C, both at-rest and in-flight. A second step
deals with the data from the implementation in the central region of the KLOE detector of a pure graphite target, providing a high statistic sample of K- 12C nuclear captures at rest. For the future a new setup, with various dedicated gaseous and solid targets, is under preparation.
Experimental results on multi-nucleonic K- absorptions in light nuclei
O. Vazques Doce, ..., E. Czerwinski, ..., W. Krzemien, ..., P. Moskal, ..., M. Silarski, et al. (AMADEUS Collaboration)
abstract
Latest discrete symmetries and Quantum Mechanics studies with KLOE-2
D. Kamińska
abstract
The KLOE-2 experiment at the INFN Laboratori Nazionali di Frascati (LNF) is currently taking data at the upgraded e (+) e? DAFNE collider, representing the continuation of KLOE with a new physics program including kaon interferometry and test of discrete symmetries among the main topics. In fact entangled neutral kaon pairs produced at DAFNE are a unique tool to probe discrete symmetries and/or QM basic principles at the utmost precision. The status of the latest ongoing analyses on KLOE data using the most refined analyses tools will be presented and discussed including prospects for KLOE-2: (i) search for decoherence and CPT violation effects in the ? ? K(S)K(L) ? ? (+) ? (?) ? (+) ? (?) decay, (ii) test of CP and CPT symmetries in K(s) semileptonic decays, (iii) test of Time reversal and CPT in transitions in ? ? K(S)K(L) ? ?e?, 3? (0) (2? (0)) decays, (iv) study of the K(S) ? ? (+) ? (?) ? (0) decay.
K- multi-nucleon absorption processes in hadronic interaction studies
R. Del Grande, ..., E. Czerwinski, ..., W. Krzemien, ..., P. Moskal, ..., M. Silarski, et al. (AMADEUS Collaboration)
abstract
The AMADEUS collaboration aims to afford unprecedented informations on the K- low-energy
interactions with light nuclei, thanks to the unique monochromatic low-momentum kaons pro-
vided by the DAFNE collider and the excellent acceptance and resolution of the KLOE detector,
used as an active target. We will report on the measurement of the yield of the K ? two nucleon
absorption process, obtained by studying Sigma0 p pairs produced in the final state of the K-12C ab-
sorptions. Further, the possible contribution of a ppK- bound state was investigated. The best fit
corresponding to a gives space to a yield of ppK-/K- stop = (0.044 ? 0.009 stat +0.004 ?0.005 syst) ×10 binding energy and a width of 45 and 30 MeV/c 2 , respectively. A statistical analysis of this result shows although that its significance is only at the level of 1sigma.
Determination of the analysing power for the vec{p} p ->pp eta reaction using WASA-at-COSY detector system
P. Adlarson, ...,E. Czerwiński, O. Khreptak, W. Krzemień, P. Moskal, O. Rundel, M. Skurzok, M. Zieliński et al. (WASA-at-COSY Collaboration)
abstract
We report on the measurement of the analyzing power for the ~ pp -> pp eta reaction with beam
momenta of 2026 MeV/c and 2188 MeV/c performed with the WASA-at-COSY detector at the
Cooler Synchrotron COSY. The eta meson from the pp -> pp eta reaction was identified by the tech-
niques of missing mass and invariant mass. The angular distribution of the determined analyzing
power strongly disagrees with theoretical predictions. A comparison of the obtained A y angular
distribution with a series of associated Legendre polynomials revealed negligible contribution of
the Sd partial wave at Q = 15 MeV. However, at Q = 72 MeV, a significant interference of the Ps
and Pp partial waves was observed.
Studies of discrete symmetries in a purely leptonic system using the Jagiellonian Positron Emission Tomograph
P. Moskal, D. Alfs, T. Bednarski, P. Białas, C. Curceanu, E. Czerwiński, K. Dulski, A. Gajos, B. Głowacz, N. Gupta-Sharma, M. Gorgol, B. C. Hiesmayr, B. Jasińska, D. Kamińska, O. Khreptak, G. Korcyl, P. Kowalski, W. Krzemień, N. Krawczyk, E. Kubicz, M. Mohammed, Sz. Niedźwiecki, M. Pawlik-Niedźwiecka, L. Raczyński, Z. Rudy, M. Silarski, J. Smyrski, A. Wieczorek, W. Wiślicki, B. Zgardzińska, and M. Zieliński
abstract
Discrete symmetries such as parity (P), charge-conjugation (C) and time reversal (T) are of fundamental importance in physics and cosmology. Breaking of charge conjugation symmetry (C) and its combination with parity (CP) constitute necessary conditions for the existence of the asymmetry between matter and antimatter in the observed Universe. The presently known sources of discrete symmetries violations can account for only a tiny fraction of the excess of matter over antimatter. So far CP and T symmetries violations were observed only for systems involving quarks and they were never reported for the purely leptonic objects. In this article we describe briefly an experimental proposal for the test of discrete symmetries in the decays of positronium atom which is made exclusively of leptons. The experiments are conducted by means of the Jagiellonian Positron Emission Tomograph (J-PET) which is constructed from strips of plastic scintillators enabling registration of photons from the positronium annihilation. J-PET tomograph together with the positronium target system enable to measure expectation values for the discrete symmetries odd operators constructed from (i) spin vector of the ortho-positronium atom, (ii) momentum vectors of photons originating from the decay of positronium, and (iii) linear polarization direction of annihilation photons. Linearly polarized positronium will be produced in the highly porous aerogel or polymer targets, exploiting longitudinally polarized positrons emitted by the sodium 22Na isotope. Information about the polarization vector of orthopositronium will be available on the event by event basis and will be reconstructed from the known position of the positron source and the reconstructed position of the orthopositronium annihilation. In 2016 the first tests and calibration runs are planned, and the
data collection with high statistics will commence in the year 2017.
Status of the analysis for the search of polarization in the antiproton production process
D. Alfs, A. Asaturyan, M. Carmignotto, M. Diermaier, W. Eyrich, B. Głowacz, D. Grzonka, F. Hauenstein, T. Horn, K. Kilian, S. Malbrunot-Ettenauer, A. Mkrtchyan, H. Mkrtchyan, P. Moskal, P. Nadel-Turonski, W. Oelert, J. Ritman, T. Sefzick, V. Tadevosyan, E. Widmann, M. Wolke, S. Zhamkochyan, M. Zieliński, A. Zink, and J. Zmeskal
abstract
The P-349 experiment aims to test whether for antiprotons the production process itself can be a source of polarization in view of the preparation of a polarized antiproton beam. In this article we present the details of performed measurements and report on the status of the ongoing analysis.
J-PET detector system for studies of the electron-positron annihilations
M. Pawlik-Niedźwiecka, O. Khreptak, A. Gajos, A. Wieczorek, D. Alfs, T. Bednarski, P. Białas, C. Curceanu, E. Czerwiński, K. Dulski, B. Głowacz, N. Gupta-Sharma, M. Gorgol, B. C. Hiesmayr, B. Jasińska, D. Kamińska, G. Korcyl, P. Kowalski, W. Krzmień, N. Krawczyk, E. Kubicz, M. Mohammed, Sz. Niedźwiecki, L. Raczyński, Z. Rudy, M. Silarski, W. Wiślicki, B. Zgardzińska, M. Zieliński, and P. Moskal
abstract
Jagiellonian Positron Emission Tomograph (J-PET) has been recently constructed at the Jagiellonian University as a prototype of a cost-effective scanner for the metabolic imaging of the whole human body. J-PET detector is optimized for the measurement of momentum and polarization of photons from the electron-positron annihilations. It is built out of strips of plastic scintillators, forming three cylindrical layers. As detector of gamma quanta it will be used for studies of discrete symmetries and multiparticle entanglement of photons originating from the decays of ortho-positronium atoms.
Searching for eta-mesic Helium with WASA-at-COSY facility
O. Rundel, O. Khreptak, M. Skurzok, W. Krzemien and P. Moskal
abstract
The search for the 4He-eta and 3He-eta bound states was performed with the WASA-at-COSY facility using a ramped beam technique in 2008, 2010 and 2014, respectively. The 2008 and 2010 data analyses has already been completed and resulted in the upper limits for the total cross sections for the eta-mesic 4He production in dd -> 3Henpi0 and dd -> 3Heppi- processes. No narrow structure which could be interpreted as a bound state was observed. The experiment carried out in 2014 collected the largest data sample for 3He-eta in the world. The data analysis is in progress. This article presents results of the 2010 data analysis and preliminary results of the 2014 data analysis.
Production and interaction of the eta meson with nucleons and nuclei
W. Krzemień, O. Khreptak, P. Moskal, I. Ozyrianska-Schaetti, O. Rundel, M. Skurzok and M. Zieliński
abstract
We report on the status of the search for eta-mesic nuclei and the studies of the interaction of the eta meson with nucleons. Recently we have completed the analysis of the new WASA-at-COSY data on the production of the eta meson with polarized proton beam. New results on the analyzing power for the p?p -> pp? reaction with more than an order of magnitude improved precision shed a new light on the production mechanism of the eta meson in nucleon-nucleon collisions. Also, the latest results of the search for eta-mesic nuclei are discussed.
Investigation of the low-energy kaons hadronic interactions in light nuclei by AMADEUS
A. Scordo, ..., P. Moskal, et all.
abstract
The AMADEUS experiment deals with the investigation of the low-energy kaon-nuclei hadronic interaction at the DAFNE collider at LNF-INFN. This study is fundamental to solve longstanding questions concerning interactions of strange quarks in the non-perturbative QCD. AMADEUS step 0 consisted in the reanalysis of the 2004/2005 KLOE data, exploiting K? absorptions in H, 4He, 9Be and 12C, leading to the first invariant mass spectroscopy study with very low momentum (100 MeV/c) in-flight K? captures. In this paper, we present an overview of the analysis strategy, with particular emphasis on the results obtained in the analyses of the events with correlated Sigma0 and p.
Search for dark forces with KLOE
A. Gajos for the KLOE and KLOE-2 Collaborations
abstract
During the last years several Dark Sector Models have been proposed in order to address striking astrophysical observations which failed standard interpretations. In the minimal case a new vector particle, the so called dark photon, or A' or U boson, is introduced, with small coupling with Standard Model particles. Also, the existence of a dark Higgs boson h' is postulated, in analogy with the Standard Model, to give mass to the U boson through the Spontaneous Symmetry Breaking mechanism. The KLOE experiment working at DAFNE, an e+e- collider operating in Frascati (near Rome), searched for the existence of the U boson investigating three different processes and six different final states: (1) in Dalitz decays of the phi meson phi->eta U, with U -> e+e- and U -> pi+pi-pi0 and pi0pi0pi0, (2) in e+e- -> Ug events, with U decaying into lepton and pion pairs, (3) in the dark Higgsstrahlung process, e+e- -> Uh', U -> mu+mu-, h' invisible. Limits on the model parameters have been set at 90 % CL for U boson masses below 1 GeV. Further improvements are expected in terms of sensitivity and discovery potential with the new KLOE-2 detector.
Theoretical studies of the reaction e+e- ->K+K-gamma
L. Leśniak, M. Silarski
abstract
We present studies of the e+e- -> K+K-gamma reaction for the e+e- center-of-mass energies close to the phi(1020) meson mass. Different mechanisms leading to the final state are considered. The strong interaction amplitudes of the K+K- pairs in the S - wave are taken into account. In addition, the photon emission in the initial state, the final state radiation effects and all the possible interference terms are included in the transition matrix elements. The K+K- effective mass distributions and the angular dependence of the reaction cross-section are calculated.
Recent Results from WASA-at-COSY
H. Clement, P. Moskal, M. Skurzok
abstract
The detector system WASA-at-COSY has been operated at the Cooler Synchrotron COSY in the years from 2006 till 2015. In this article we report on recent results of the analyses of the meson production reactions in nucleon?nucleon, nucleon?deuteron, and deuteron?deuteron collisions with spin-polarized and unpolarized beams emphasizing the evidences for the existence of the dibaryon state in the proton-neutron system and the perspectives for the search of the eta-mesic helium.
A novel TOF-PET detector based on plastic scintillators
W. Krzemien, D. Alfs, T. Bednarski, P. Białas, E. Czerwiński, K. Dulski, A. Gajos, B. Głowacz, M. Gorgol, ´ B. Jasińska, D. Kamińska, Ł. Kapłon, G. Korcyl, P. Kowalski, T. Kozik, E. Kubicz, M. Mohammed, ´ Sz. Niedźwiecki, M. Pałka, M. Pawlik-Niedźwiecka, L. Raczyński, Z. Rudy, O. Rundel, N.G. Sharma, M. Silarski, A. Słomski, K. Stola, A. Strzelecki, A. Wieczorek, W. Wiślicki, B. K. Zgradzińska, M. Zieliński, P. Moskal
abstract
The Jagiellonian-PET (J-PET) collaboration is developing
a novel TOF-PET tomography scanner based mainly
on the timing of signals instead of their amplitudes for the
reconstruction of Lines-of-Response, therefore a very precise time
resolution is one of the main challenges of the project. The
novelty of the concept lies in employing long strips of plastic
scintillators instead of crystals as detectors of the annihilation
quanta. The diagnostic chamber consists of plastic scintillator
strips readout by pairs of photomultipliers arranged axially
around a cylindrical surface. To take advantage of the superior
timing properties of plastic scintillators, the signals are sampled
in the voltage domain with an accuracy of 20 ps by novel ultrafast
electronics, and the data are collected by the FPGA-based
trigger-less data acquisition system. The hit-position and hittime
are reconstructed by the dedicated reconstruction methods
based on the compressing sensing theory and a library of
synchronized model signals. The solutions are subject of sixteen
patent applications. So far, a time-of-flight resolution of 125 ps
(?) was achieved for a double-strip prototype with 30 cm fieldof-view
(FOV). It is by more than a factor of two better than the
TOF resolution achievable in current TOF-PET modalities and
at the same time, the FOV of 30 cm long prototype is significantly
larger with respect to typical commercial PET devices. The axial
geometry gives unique possibilities of combining J-PET with
Computed Tomography or with Magnetic Resonance Imaging,
allowing to perform the simultaneous scan of the patient with
both methods.
The KLOE-2 experiment at DAFNE
M. Silarski
abstract
The KLOE-2 experiment at the INFN Laboratori Nazionali di Frascati (LNF) is currently taking data at the upgraded e+e- DAFNE collider. Present Run II follows a development phase to assess the feasibility of a long term acquisition program, Run I, which successfully ended in July 2015 with 1 fb-1 integrated luminosity collected in less than eight months. KLOE-2 represents the continuation of the KLOE experiment with a new physics program. The KLOE detector has undergone several upgrades including state-of-the-art cylindrical GEM Inner Tracker, electron-positron taggers for the gammagamma-physics studies and new calorimeters around the interaction point. In this article we briefly present the overview of the KLOE-2 experiment including the present status and achievements together with the physics plans.
Recent KLOE results on kaon physics
E. Czerwiński on behalf of the KLOE-2 Collaboration
abstract
A short review of two measurements recently published by KLOE/KLOE-2 collaborations is presented. Namely the most stringent limits of the CPT-violating parameters Delta a_mu for neutral kaons, and the absolute branching ratio of K+->pi+pi-pi+(gamma) decay. In addition a discussion of starting KLOE-2 project is performed.
Status and Perspectives of the Search for Eta-Mesic Nuclei
P. Moskal, M. Skurzok, W. Krzemień
abstract
In this report the search for eta-mesic nuclei is reviewed. The brief description ofeta-nucleus bound states for light nuclei like 4He and 3He.
Search for the eta-mesic Helium bound state with the WASA-at-COSY facility
M. Skurzok, W. Krzemien, O. Rundel, P. Moskal
abstract
We performed a search for 4He-eta bound state with high statistics and high acceptance with the WASA-at-COSY facility using a ramped beam technique. The signature of eta-mesic nuclei is searched for in dd -> 3Henpi0 and dd -> 3Heppi- reactions by the measurement of the excitation functions in the vicinity of the {eta} production threshold. This paper presents the experimental method and the preliminary results of the data analysis for dd -> 3Henpi0 process.
Study of KS semileptonic decays and CPT test with the KLOE detector
D. Kamińska on behalf of the KLOE-2 collaboration
abstract
Study of semileptonic decays of neutral kaons allows to perform a test of discrete symmetries, as well as basic principles of the Standard Model. In this paper a general review on dependency between charge asymmetry constructed for semileptonic decays of short- and long-lived kaons and CPT symmetry is given. The current status of determination of charge asymmetry for short-lived kaon, obtained by reconstruction of about 10^5 KS->pen decays collected at DAFNE with the KLOE detector is also reviewed
A direct test of T symmetry in the neutral K meson system at KLOE-2
Aleksander Gajos (on behalf of theKLOE-2 Collaboration)
abstract
This work presents prospects for conducting a novel direct test of time-reversal symmetry at the KLOE-2 experiment. Quantum entanglement of neutral K meson pairs uniquely available at KLOE-2 allows to probe the T symmetry directly and independently of CP violation. This is achieved by a comparison of probabilities for a transition and its inverse obtained through an exchange of initial and final states. Such transitions between flavor and CP-definite states of the neutral kaons are only connected by the T conjugation which ensures the CP-independence of the test. While a similar measurement was performed by the BaBar experiment with neutral B mesons, the KLOE-2 detector can test T-violation in the neutral kaons system. Such a test requires i.a. reconstruction of the KL -> 3pi0 decay accompanied by Ks -> pienu with good timing information. Therefore a new reconstruction method for the KL -> 3pi0 decay is also presented which is capable of reconstructing this process with decay time resolution of O(1 tauS).
Search for the 4He-eta bound state in dd->(4He-eta)_{bound}->3He n pi0 and dd->(4He-eta)_{bound}->3He p pi- reactions with the WASA-at-COSY facility
M. Skurzok , W. Krzemień, P. Moskal
abstract
In November 2010, the search for the 4He-{eta} bound state was per formed with high statistics and high acceptance with the WASA-at-COSY facility using a ramped beam technique. The signature of eta - mesic nuclei is searched for in the measured excitation functions for the two reaction channels: dd ->3He n pi0 and dd ->3He p pi- near the eta production threshold. This report includes the description of the experimental method and the status of the data analysis.
Close to threshold eta' meson production in proton-proton collisions at COSY-11
E. Czerwiński, P. Moskal, M. Silarski
abstract
Intensive quest for the eta and eta' bound states is currently ongoing at both theoretical and experimental levels e.g. at COSY, ELSA, GSI, JINR, JPARC, LPI, and MAMI. These studies were already supported by data provided by the COSY-11 collaboration including determination of the total width of the eta' meson. In addition, the first rough estimation of the eta'-N interaction from the excitation function of the cross section for the pp-->pp eta' reaction was also performed. Recent precise measurement in this field from the COSY-11 experiment allows to summarize results on the eta' meson production cross section in proton-proton collisions at COSY-11.
A direct test of time-reversal symmetry in the neutral K meson system with KS -> pi e nu and KL -> 3pi0 at KLOE-2
A. Gajos on behalf of the KLOE-2 Collaboration
abstract
Quantum entanglement of K and B mesons allows for a direct experimental test of time-reversal symmetry independent of CP violation. The T symmetry can be probed by exchange of initial and final states in the reversible transitions between flavor and CP- definite states of the mesons which are only connected by the T conjugation. While such a test was successfully performed by the BaBar experiment with neutral B mesons, the KLOE-2 detector can probe T -violation in the neutral kaons system by investigating the process with KS ? ??l??l and KL ? 3?0 decays. Analysis of the latter is facilitated by a novel reconstruction method for the vertex of KL ? 3?0 decay which only involves neutral particles. Details of this new vertex reconstruction technique are presented as well as prospects for conducting the direct T symmetry test at the KLOE-2 experiment.
Polarization determination for the studies of the eta meson production
I. Ozerianska, P. Moskal, M. Zieliński
abstract
The dynamics of ? meson production and the interaction of ? mesons with nucleons can be studied using the ?p p?pp? reaction via measurements of the analyzing power Ay. To this end, we have performed a measurement of the ?p p ?pp? reaction using the large acceptance and ? symmetric WASA-at-COSY detector, for beam momenta of 2026 MeV/c and 2188 MeV/c.
Status of the measurement of KS -> nev branching ratio and lepton charge asymmetry with the KLOE detector
D. Kamińska on behalf of the KLOE-2 collaboration
abstract
We present the current status of the analysis of about 1.7 billion KS KL pair events collected at DA?NE with the KLOE detector to determine the branching ratio of KS ? ?e? decay and the lepton charge asymmetry. This sample is ? 4 times larger in statistics than the one used in the previous most precise result, from KLOE as well, allowing us to improve the accuracy on the measurement and related tests of CPT symmetry and ?S = ?Q rule.
Status of KS -> pi e nu branching ratio and lepton charge asymmetry measurements with the KLOE detector
D. Kamińska for KLOE-2 Collaboration
abstract
Study of the KSKl->pi l nu 3pi0 process for a direct test of T symmetry at KLOE-2
A. Gajos for the KLOE-2 Collaboration
abstract
The eta-meson production with the polarized proton beam with WASA-at-COSY
I. Ozerianska, M. Hodana , P. Moskal
abstract
In November 2010, the azimuthal symmetric WASA detector and the polarized proton beam of COSY, have been used to collect a high statistics sample of (vec)p->ppeta reactions in order to determine the analyzing power as a function of the invariant mass spectra of the two particle subsystems. Here, we show studies of the infuence of the beam and target characteristics such as location and direction on the determination of the polarization.
Search for a dark photon with the WASA detector at COSY
Pawel Moskal for WASA at COSY Collaboration
abstract
49th Rencontres de Moriond QCD and High Energy Interactions
We present recent results on the search for the U boson based on the data collected by means of the WASA detector and the Cooler Synchrotron COSY.
Search for the eta-mesic 4He with WASA-at-COSY
W. Krzemien, P. Moskal, J. Smyrski and M. Skurzok
abstract
We conduct a search for the He ? ? bound state with the WASA-at-COSY facility measuring the excitation functions for the reaction channels: dd ? 3Hep?? and dd ? 3Hen?0, where the outgoing N ? ? pairs originate from the conversion of the ? meson on a nucleon inside the He nucleus. Two dedicated experiments were performed at the Cooler Synchrotron COSY-Jülich with the WASA detector. The analysis of the 2008 data shows no signal of the 4He ? ? bound state. An upper limit for the cross-section for the bound state formation and decay in the process dd ? (4He ? ?)bound ? 3Hep??, was determined at the 90 % confidence level. In November 2010 a new data set was collected.
Tracking with straw tubes in the PANDA experiment
M. Bragadireanu, ..., S. Jowzaee, et al.
abstract
The PANDA spectrometer will be built at the FAIR facility at Darmstadt (Ger-
many) to perform accurate tests of the strong interaction through
?
pp and
?
pA annihilation
studies. The charged particle tracking at PANDA will be done using both solid state and
gaseous detectors. Among the latter, two straw tube detector systems will be built [1].
The cylindrical, central straw tube tracker features a high spatial and momentum resolu-
tion for a wide range of particle momenta from about 8 GeV
/
c down to a few 100 MeV
/
c,
together with particle identification in the momentum region below about 1 GeV
/
c by
measuring the specific energy-loss. A new technique, based on self-supporting straw
double layers with intrinsic wire tension developed for the COSY-TOF straw tracker [2],
has been adopted for the PANDA trackers. The development of the readout electronics for
the straw tubes is ongoing. Prototypes have been produced and used to instrument straw
tube modules that have been tested with cosmic rays and proton beams. Design issues of the PANDA straw tubes, ogether with the results of the prototype tests are presented.
Search for the eta-mesic helium by means of WASA detector at COSY
P. Moskal, W. Krzemień, M. Skurzok
abstract
PoS Hadron2013 (2014) 163
The eta-mesic nuclei in which the eta meson is bound with nucleus via strong interaction was postulated about 25 years ago, however till now no experiment confirmed empirically its existence. The discovery of this new kind of an exotic nuclear matter would be very important for better understanding of the eta meson structure and its interaction with nucleons. The search for eta-mesic helium is carried out with high statistic and high acceptance with the WASA-at-COSY detection setup and the Cooler Synchrotron COSY. The search is conducted via the measurement of the excitation function for the chosen decay channels of the 4He-eta system. Until now two reactions dd -> (4He-eta)bound ->3Heppi- and dd -> (4He-eta)bound ->3Henpi0 have been measured with the beam momentum varied continuously around the eta meson production threshold. This contribution includes description of recently published results of the WASA-at-COSY experiment as well as brief presentation of preliminary results from the analysis of new data sample with 20 times larger statistics.
System Response Kernel Calculation for List-mode Reconstruction in Strip PET Detector
P. Białas, J. Kowal, A. Strzelecki, T. Bednarski, E. Czerwiński, Ł. Kapłon, A. Kochanowski, G. Korcyl, P. Kowalski, T. Kozik, W. Krzemień, M. Molenda, P. Moskal, Sz. Niedźwiecki, M. Pałka, M. Pawlik, L. Raczyński, Z. Rudy, P. Salabura, N. Gupta-Sharma, M. Silarski, A. Słomski, J. Smyrski, W. Wiślicki, M. Zieliński
abstract
Reconstruction of the image in Positron Emission Tomographs (PET) requires the knowledge of the system response kernel which describes the contribution of each pixel (voxel) to each tube of response (TOR). This is especially important in list-mode reconstruction systems, where an efficient analytical approximation of such function is required. In this contribution, we present a derivation of the system response kernel for a novel 2D strip PET.
Studies of Systematic Uncertainties of Polarization Estimation for Experiments with the WASA Detector at COSY
M. Hodana, P. Moskal, I. Ozerianska
abstract
In November 2010, the azimuthally symmetric WASA detector and the polarized proton beam of COSY have been used to collect a high statistics sample of ?p p ? pp? reactions in order to determine the analyzing power as a function of the invariant mass spectra of the two-particle subsystems. Here, we show studies of the influence of the beam and target characteristics such as location and direction on the determination of degree of the polarization.
Quantum Mechanics and CPT Tests with Neutral Kaons at the KLOE Experiment
I. Balwierz-Pytko
abstract
Neutral kaons produced in the correlated pairs at the DA?NE ?-factory offer unique possibilities to perform fundamental tests of CPT invariance, as well as of the basic principles of quantum mechanics. The analysis of the data collected by the KLOE experiment allows to improve results on several parameters describing CPT violation and decoherence, and to measure the regeneration cross section on the beam pipe materials.
Applications of Neutron Activation Spectroscopy
M. Silarski
abstract
Since the discovery in 1932, neutrons became a basis of many methods used not only in research, but also in industry and engineering. Among others, the exceptional role in the modern nuclear engineering is played by the neutron activation spectroscopy, based on the interaction of neutron flux with atomic nuclei. In this article, we shortly describe application of this method in medicine and detection of hazardous substances.
Studies on Antihydrogen Atoms with the ATRAP Experiment at CERN
M. Zieliński, et al.
abstract
The CPT theorem predicts the same properties of matter and antimatter, however, in the nearby Universe, we observe a huge imbalance of matter and antimatter. Therefore, it is intriguing to measure the properties of particles and antiparticles in order to contribute to an explanation of this phenomena. In this article, we will describe the experimental efforts of the ATRAP Collaboration in order to test the CPT theorem using antihydrogen atoms.
Development of CGEM Technology for Ultra-light Tracking Detectors: the KLOE-2 Inner Tracker
A. Balla, G. Bencivenni, P. Branchini, A. Budano, M. Capodiferro, S. Cerioni, P. Ciambrone, E. Czerwiński, et al.
abstract
KLOE-2 at the ?-factory DA?NE of INFN Laboratori Nazionali di Frascati (LNF), is the first experiment using the GEM technology with a cylindrical geometry (CGEM), developed at the LNF by the Inner Tracker group and within the RD51 Collaboration. Four layers with 26÷41 cm diameters and L = 70 cm, each realized as a Triple-GEM detector, compose this new detector. To produce GEM foils of unprecedented size, the novel single-mask manufacturing procedure has been developed with the TE-MPE-EM CERN group, together with the realization of a novel XV readout pattern. The adopted solutions allowed the total material budget to be kept below 2% of the radiation length X0. The final assembly of the Inner Tracker has been completed on March 14, 2014. The production procedure will be reported together with the validation test results.
Application of Compressive Sensing Theory for the Reconstruction of Signals in Plastic Scintillators
L. Raczyński, P. Kowalski, T. Bednarski, P. Białas, E. Czerwiński, Ł. Kapłon, A. Kochanowski, G. Korcyl, J. Kowal, T. Kozik, W. Krzemień, M. Molenda, P. Moskal, Sz. Niedźwiecki, M. Pałka, M. Pawlik, Z. Rudy, P. Salabura, N.G. Sharma, M. Silarski, A. Słomski, J. Smyrski, A. Strzelecki, W. Wiślicki, M. Zieliński
abstract
Compressive Sensing theory says that it is possible to reconstruct a measured signal if an enough sparse representation of this signal exists in comparison to the number of random measurements. This theory was applied to reconstruct signals from measurements of plastic scintillators. Sparse representation of obtained signals was found using SVD transform.
Search for eta-mesic helium via deuteron-deuteron reactions with the WASA-at-COSY facility
M. Skurzok, P. Moskal, W. Krzemień
abstract
The eta-mesic nuclei in which the eta meson is bound with nucleus via strong interaction was postulated already in 1986, however till now no experiment confirmed empirically its existence. The discovery of this new kind of an exotic nuclear matter would be very important for better understanding of the eta meson structure and its interaction with nucleons. The search for eta-mesic helium is carried out with high statistic and high acceptance with the WASA-at-COSY detection setup in the Forschungszentrum Julich. The search is conducted via the measurement of the excitation function for the chosen decay channels of the 4He-eta system. Untill now two reactions dd->(4He-eta)bs->3He p pi- and dd->(4He-eta)bs->3He n pi0 have been measured with the beam momentum ramped around the eta production threshold. This report includes the description of experimental method and status of the analysis.
Search for eta-mesic helium via the dd->(4He-eta)_bs -> 3He n pi 0 reaction with the WASA-at-COSY facility
M. Skurzok, W. Krzemień, P. Moskal
abstract
The existence of eta-mesic nuclei in which the $eta$ meson is bound in a nucleus by means of the strong interaction was postulated already in 1986 but it has not been yet confirmed experimentally. The discovery of this new kind of an exotic nuclear matter would be very important as it might allow for a better understanding of the eta meson structure and its interaction with nucleons. The search for eta-mesic helium (4He-eta) is carried out with high statistics and high acceptance with the WASA detector, installed at the cooler synchrotron COSY of the Research Center Juelich. The search is conducted via the measurement of the excitation function for selected decay channels of the 4He-eta system. In the experiment, performed in November 2010, two reactions dd-->4He-eta-->3He p pi- and dd-->4He-eta-->3He n pi0 were measured with a beam momentum ramped from 2.127GeV/c to 2.422GeV/c. The proceedings will include description of the experimental method of the analysis.
Validation of spallation models : An Approach
S. Sharma
abstract
To understand and describe the proton-induced spallation reactions, a large number of computer codes have been proposed. Various quantitative tests are used in literature to judge the agreement between model calculations and experimental data. The judgment is based on the magnitude of the deviation of the tests from their expected values in the case of the perfect agreement. However, the expected values of the tests and their standard deviations are usually not well known. Thus the conclusions may be ambiguous. It is proposed to calculate the expected values and standard deviations of the tests by the Monte Carlo method and to use the tests in their
standardized form.
Status and perspectives of the KLOE-2 experiment
F. Achilli, ..., I. Balwierz, E. Czerwiński, P. Moskal, M. Silarski, J. Zdebik et al.
abstract
The KLOE experiment has acquired an integrated luminosity greater than 2.5 fb?1 at the peak of ?-resonance on the e+e? DA?NE collider in the Frascati National Laboratory (LNF). New data taking with the upgraded detector (KLOE-2) and DA?NE should start in the end of 2011. Main modifications of the detector and new interaction region give a unique possibility to collect about 20 fb?1 in 3 years. The KLOE-2 wide scientific program which contains the experimental study of CP and CPT symmetries, quantum decoherence, ?? physics and search of the dark matter is presented and briefly discussed.
Recent results on hadron physics at KLOE
D. Babusci, ..., I. Balwierz - Pytko, E. Czerwiński, A. Gajos, K. Kacprzak, P. Moskal, M. Silarski, W. Wiślicki, J. Zdebik et al.
abstract
One of the basic motivations of the KLOE and KLOE-2 collaborations is the test of fundamental symmetries and the search for phenomena beyond the Standard Model via the hadronic and leptonic decays of ground-state mesons and via their production in the fusion of virtual gamma quanta exchanged between colliding electrons and positrons. This contribution includes brief description of results of recent analysis of the KLOE data aimed at (i) the search for the dark matter boson, (ii) determination of the hadronic and light-by-light contributions to the g-2 muon anomaly and (iii) tests of QCD anomalies.
Search for eta-mesic 4He with WASA-at-COSY detector.
W. Krzemień, P. Moskal, M. Skurzok, J. Smyrski
abstract
PoS Bormio2013 (2013) 036
Search for 4He-eta bound states with the WASA-at-COSY facility
M. Skurzok, W. Krzemien, P. Moskal
abstract
Test of charge conjugation invariance in the decay of the eta meson into pi(+)pi(-)pi(0)
M. Zieliński, P. Moskal
abstract
In this work we present the preliminary results of the analysis of the pp->pp
eta(->pp pi(+)pi(-)pi(0) reaction aiming to test the charge conjugation
symmetry C in strong interactions. Based on approximately $10^5$ identified
eta->pi(+)pi(-)pi(0) decay events we have extracted asymmetry parameters
sensitive to C symmetry violation for different isospin values of the final
state and we have established that all are consistent with zero within the
obtained accuracy.
Search for the Ks-->3pi0 decay with the KLOE detector
M. Silarski
abstract
The Ks-->3pi0 decay is a pure CP violating process which, assuming CPT invariance, allows one to investigate direct CP violation. This decay has not been observed so far, and the best upper limit on the branching ratio BR(Ks-->3pi0) < 1.2 x 10-7 is two orders of magnitude larger than predictions based on the Standard Model. In this article we present the search for the Ks-->3pi0 decay performed with the KLOE detection system operating at the DAFNE phi-factory at the Frascati Laboratory of the Italian Institute of Nuclear Physics. We describe the experimental techniques used in the background rejection and signal events selection as well as the evaluation of almost five times lower upper limit on the Ks-->3pi0 branching ratio. We discuss shortly also the perspectives for a new measurement using the KLOE-2 apparatus equipped with a new inner tracker and the calorimeters at low theta angle.
Search for eta-mesic Helium with the WASA-at-COSY detector.
W. Krzemień, P. Moskal, J. Smyrski, M. Skurzok
abstract
A search for the 4He-eta bound state via exclusive measurement of the excitation function for the dd->3Heppi- reaction, was performed at the Cooler Synchrotron COSY-Juelich with the WASA-at-COSY detection system. The data were taken during a slow acceleration of the beam from 2.185 GeV/c to 2.400 GeV/c crossing the kinematic threshold for the eta production in the dd -> 4He-eta reaction at 2.336 GeV/c. The corresponding excess energy in the 4He-eta system varied from -51.4 MeV to 22 MeV. The shape of the excitation function for the dd -> 3Heppi- was examined. No signal of the 4He-eta bound state was observed in the excitation function.
Study of the eta -> e+ e-gamma Decay Using WASA-at-COSY Detector System
M. Hodana, P. Moskal for the WASA - at - COSY Collaboration
abstract
At the turn of October and November 2008, the WASA-at-COSY collaboration performed an experiment to collect data on the eta meson decays in pd-->3He eta reactions. This report presents results of a study of the eta-->e+e-g conversion decay. The desired feature of this decay is that the final state e+e- pairs come from the conversion of a virtual gamma quantum and, therefore, they constitute a rich source of knowledge about the electromagnetic structure of decaying meson. This is a very important characteristic when it comes to study of a short-lived neutral particle like the eta meson, because the classical methods of particle scattering are not applicable here. The analysis performed on one third of the p-d data sample collected using the WASA-at-COSY detector, lead to the extraction of the eta transition form factor as a function of the e+e- mass and to the calculation of the slope parameter, related to the charge radius of the eta meson.
Search for the He-eta bound states with the WASA-at-COSY facility
M. Skurzok, W. Krzemień, P. Moskal
abstract
The existence of eta-mesic nuclei in which the $eta$ meson is bound in a nucleus by means of the strong interaction was postulated already in 1986 but it has not been yet confirmed experimentally. The discovery of this new kind of an exotic nuclear matter would be very important as it might allow for a better understanding of the eta meson structure and its interaction with nucleons. The search for eta-mesic helium (4He-eta) is carried out with high statistics and high acceptance with the WASA detector, installed at the cooler synchrotron COSY of the Research Center Juelich. The search is conducted via the measurement of the excitation function for selected decay channels of the 4He-eta system. In the experiment, performed in November 2010, two reactions dd-->4He-eta-->3He p pi- and dd-->4He-eta-->3He n pi0 were measured with a beam momentum ramped from 2.127GeV/c to 2.422GeV/c. The poster will include description of the experimental method and status of the analysis.
Recent results on CP and CPT tests at KLOE/KLOE-2
A. Di Domenico, M. Silarski, on behalf of the KLOE-2 collaboration
abstract
Nuclear Physics B Proc. Suppl. 233 (2012) 73
Neutral kaon pairs produced in phi decays offer a unique possibility to perform fundamental tests of discrete symmetries. Among the most recent results obtained by the KLOE experiment at DAFNE, the Frascati phi-factory, there is the new best limit on the branching ratio of the CP-violating decay Ks --> 3pi0, BR < 2.6 x 10^?8
at 90% C.L..The search for possible violations of the CPT symmetry and Lorentz invariance in the context of the Standard-Model Extension (SME) is also described; the new analysis approach fully exploits quantum interferometry in phi --> KsKl -->pi+pi?, pi+pi? decays. Finally the status and perspectives of the new data taking campaign with the KLOE-2 experiment at the upgraded DAFNE machine are briefly reviewed.
MATRIX-PET: A novel PET detector concept based on large blocks of organic scintillators
P. Moskal, T. Bednarski, A. Heczko, M. Kajetanowicz, Ł. Kapłon, A. Kochanowski, G. Konopka - Cupiał, G. Korcyl, W. Krzemień, K. Łojek, W. Migdał, M. Molenda, S. Niedzwiecki, P. Salabura. M. Silarski, A. Słomski, J. Smyrski, Z. Rudy, J. Zdebik, M. Zieliński
abstract
Matrix-PET is a novel detector solution for the Positron Emission Tomography. It is one of the
two methods which is developed at present at the Jagiellonian University.
STRIP-PET: Concept of TOF-PET scanner based on polymer scintillator strips
P. Moskal, T. Bednarski, A. Heczko, M. Kajetanowicz, Ł. Kapłon, A. Kochanowski, G. Konopka - Cupiał, G. Korcyl, W. Krzemień, K. Łojek, W. Migdał, M. Molenda, S. Niedźwiecki, P. Salabura. M. Silarski, A. Słomski, J. Smyrski, Z. Rudy, J. Zdebik, M. Zieliński
abstract
The aim of the poster is to present an idea of a new PET scanner based on strips of polymer scintillators
arranged in a large acceptance detector system which may allow a simultaneous diagnostic
of a large fraction of (or even the whole) human body.
Polymer Scintillator Detectors for TOF-PET with Large Longitudinal Field of View
P. Moskal, T. Bednarski, A. Heczko, M. Kajetanowicz, Ł. Kapłon, A. Kochanowski, G. Konopka - Cupiał, G. Korcyl, W. Krzemień, K. Łojek, W. Migdał, M. Molenda, S. Niedzwiecki, P. Salabura. M. Silarski, A. Słomski, J. Smyrski, Z. Rudy, J. Zdebik, M. Zieliński
abstract
In this contribution we present a concept of the large acceptance detector systems based on
the organic scintillators which in the future may allow for simultaneous diagnostic of large fraction
of the human body.
Study of eta Meson Production with a Polarized Proton Beam
I. Ozerianska, P. Moskal, M. Hodana for the WASA-at-COSY Collaboration
