High precision X-ray spectroscopy of kaonic neon
F. Sgaramella, D. Sirghi, K. Toho, F. Clozza, L. Abbene, C. Amsler, M. Bazzi, G. Borghi, D. Bosnar, A. M. Bragadireanu, A. Buttacavoli, M. Cargnelli, M. Carminati, A. Clozza, R. Del Grande, L. De Paolis, K. Dulski, L. Fabbietti, C. Fiorini, I. Friscic, C. Guaraldo, M. Iliescu, M. Iwasaki, A. Khreptak, S. Manti, J. Marton, P. Moskal, F. Napolitano, S. Niedźwiecki, H. Onishi, K. Piscicchia, F. Principato, A. Scordo, M. Silarski, F. Sirghi, M. Skurzok, A. Spallone, L. G. Toscano, M. Tuchler, O. Vazquez Doce, E. Widmann, J. Zmeskal, C. Curceanu

abstract
The high-precision kaonic neon X-ray transitions measurement performed by the SIDDHARTA-2 collaboration at the DAFNE collider is reported. Both the X-ray energies and yields for high-n transitions were measured, demonstrating the feasibility of sub-eV X-ray spectroscopy for kaonic atoms using low-Z gaseous targets. The measurement provides valuable insights into the de-excitation processes in kaonic atoms, providing new input data for the refinement of the corresponding theoretical models, and a framework for testing Quantum Electrodynamics in strange exotic atoms.
Kaonic Atoms with the SIDDHARTA-2 Experiment at DAFNE
F. Napolitano, L. Abbene, F. Artibani, M. Bazzi, G. Borghi, D. Bosnar, M. Bragadireanu, A. Buttacavoli, M. Carminati, M. Cargnelli, A. Clozza, F. Clozza, G. Deda, L. De Paolis, R. Del Grande, K. Dulski, C. Fiorini, I. Friščić, C. Guaraldo, M. Iliescu, M. Iwasaki, A. Khreptak, S. Manti, J. Marton, P. Moskal, S. Niedźwiecki, H. Ohnishi, K. Piscicchia, F. Principato, A. Scordo, F. Sgaramella, D. Sirghi, F. Sirghi, M. Skurzok, M. Silarski, A. Spallone, K. Toho, L.G. Toscano, M. Tüchler, O. Vazquez Doce, J. Zmeskal, C. Curceanu

abstract
The SIDDHARTA-2 experiment aiming at measuring for the first time the X-ray transitions in kaonic deuterium, has successfully completed its 2024 physics run at the DAFNE collider of the INFN Laboratori Nazionali di Frascati. This work presents an overview of the scientific and technical achievements of SIDDHARTA-2 so far, including the most precise measurement of kaonic helium-4 Lalpha transitions and yields in gas, the observation of the kaonic helium-4 M-series transitions, and the measurement of high-n transitions in kaonic carbon, oxygen, nitrogen, and aluminium. The results of these measurements are discussed in the context of the kaonic atoms physics program at DA?NE, including future prospects within the EXKALIBUR proposal.
SIDDHARTA-2 apparatus for kaonic atoms research on the DAFNE collider
F. Sirghi, F. Sgaramella, L. Abbene, C. Amsler, M. Bazzi, G. Borghi, D. Bosnar, M. Bragadireanu, A. Buttacavoli, M. Carminati, M. Cargnelli, A. Clozza, G. Deda, L. De Paolis, R. Del Grande, K. Dulski, L. Fabbietti, C. Fiorini, I. Friščić, C. Guaraldo, M. Iliescu, M. Iwasaki, A. Khreptak, S. Manti, J. Marton, M. Miliucci, P. Moskal, F. Napolitano, S. Niedźwiecki, H. Ohnishi, K. Piscicchia, F. Principato, A. Scordo, D. Sirghi, M. Skurzok, M. Silarski, A. Spallone, K. Toho, L. Toscano, M. Tüchler, O. Vazquez Doce, C. Yoshida, J. Zmeskal, C. Curceanu

abstract
SIDDHARTA-2 represents a state-of-the-art experiment designed to perform dedicated measurements of kaonic atoms, which are particular exotic atom configurations composed of a negatively charged kaon and a nucleus. Investigating these atoms provides an exceptional tool to comprehend the strong interactions in the non-perturbative regime involving strangeness. The experiment is installed at the DAFNE electron-positron collider, of the INFN National Laboratory of Frascati (INFN-LNF) in Italy, aiming to perform the first-ever measurement of the 2p->1s X-ray transitions in kaonic deuterium, a crucial step towards determining the isospin-dependent antikaon-nucleon scattering lengths. Based on the experience gained with the previous SIDDHARTA experiment, which performed the most precise measurement of the kaonic hydrogen 2p->1s X-ray transitions, the present apparatus has been upgraded with innovative Silicon Drift Detectors (SDDs), distributed around a cryogenic gaseous target placed in a vacuum chamber at a short distance above the interaction region of the collider. We present a comprehensive description of the SIDDHARTA-2 setup including the optimization of its various components during the commissioning phase of the collider.
A feasibility study of the measurement of kaonic lead X-rays at DAFNE for the precise determination of the charged kaon mass
D. Bosnar, L. Abbene, C. Amsler, F. Artibani, M. Bazzi, A. Buttacavoli, M. Carminati, M. Cargnelli, A. Clozza, F. Clozza, G. Deda, L. De Paolis, R. Del Grande, K. Dulski, L. Fabbietti, C. Fiorini, I. Friščić, C. Guaraldo, M. Iliescu, M. Iwasaki, A. Khreptak, M. Makek S. Manti, J. Marton, P. Moskal, F. Napolitano, S. Niedźwiecki, H. Ohnishi, K. Piscicchia, A. Scordo, F. Sgaramella, D. Sirghi, F. Sirghi, M. Skurzok, M. Silarski, A. Spallone, K. Toho, M. Tüchler, O. Vazquez Doce, J. Zmeskal, C. Curceanu

abstract
An HPGe detector equipped with a transistor reset preamplifier and readout with a CAEN DT5781 fast pulse
digitizer was employed in the measurement of X-rays from kaonic lead at the DAFNE e+e- collider at the
Laboratori Nazionali di Frascati of INFN. A thin scintillator in front of a lead target was used to select kaons
impinging on it and to form the trigger for the HPGe detector. We present the results of the kaonic lead
feasibility measurement, where we show that the resolution of the HPGe detector in regular beam conditions
remains the same as that without the beam and that a satisfactory background reduction can be achieved.
This measurement serves as a test bed for future dedicated kaonic X-rays measurements for the more precise
determination of the charged kaon mass.
The SIDDHARTA-2 experiment for high precision kaonic atoms X-ray spectroscopy at DAFNE
F. Sgaramella, L. Abbene, C. Amsler, F. Artibani, M. Bazzi, D. Bosnar, M. Bragadireanu, A. Buttacavoli, M. Cargnelli, M. Carminati, A. Clozza, F. Clozza, G. Deda, R. Del Grande, L. De Paolis, K. Dulski, L. Fabbietti, C. Fiorini, I. Friščić, C. Guaraldo, M. Iliescu, M. Iwasaki, A. Khreptak, S. Manti, J. Marton, P. Moskal, F. Napolitano, S. Niedźwiecki, H. Ohnishi, K. Piscicchia, F. Principato, A. Scordo, M. Silarski, D. Sirghi, F. Sirghi, M. Skurzok, A. Spallone, K. Toho, M. Tüchler, O. Vazquez Doce, J. Zmeskal, C. Curceanu

abstract
High precision X-ray spectroscopy of light kaonic atoms provides
valuable information on kaon-nucleus interaction at threshold, allowing to investigate
the strong interaction in the strangeness sector at the low-energy frontier. The
SIDDHARTA-2 experiment at the DAFNE collider of INFN-LNF is performing the
challenging measurement of the kaonic deuterium 2p->1 s transition which together
with the kaonic hydrogen measurement performed by SIDDHARTA, will allow to
extract the isospin-dependent antikaon-nucleon scattering lengths. To achieve this
goal, the optimization of the setup to maximize the signal over background ratio
is a crucial step. This paper presents the SIDDHARTA-2 experiment and its optimization
through the first observation of kaonic neon transitions. The excellent
electromagnetic background reduction factor (~10^4) paves the way not only to the
measurement of kaonic deuterium, but also to a new era of selected kaonic atom
measurements along the periodic table.
The Odyssey of kaonic atoms studies at the DAFNE collider: From DEAR to SIDDHARTA-2
F. Artibani, F. Clozza, M. Bazzi, C. Capoccia, A. Clozza, L. De Paolis, K. Dulski, C. Guaraldo, M. Iliescu, A. Khreptak, S. Manti, F. Napolitano, O. Vazquez Doce, A. Scordo, F. Sgaramella, F. Sirghi, A. Spallone, M. Cargnelli, J. Marton, M. Tüchler, J. Zmeskal, L. Abbene, A. Buttacavoli, F. Principato, D. Bosnar, I. Friščić, M. Bragadireanu, G. Borghi, M. Carminati, G. Deda, C. Fiorini, R. Del Grande, M. Iwasaki, P. Moskal, S. Niedźwiecki, M. Silarski, M. Skurzok, H. Ohnishi, K. Toho, D. Sirghi, K. Piscicchia, C.O. Curceanu

abstract
In this paper, an overview of kaonic atoms studies from the late 90s to nowadays at the DAFNE collider at INFN-LNF is presented. Experiments on kaonic atoms are an important tool to test and optimize phenomenological models on the low-energy strong interaction. Since its construction, the DAFNE collider has represented an ideal machine to perform kaonic atoms measurements, thanks to the unique beam of kaons coming from the Phi_s produced in the collider decays. The DEAR and SIDDHARTA experiments achieved the precise evaluation of the shift and width of the 2p -> 1s transition in kaonic hydrogen due to the strong interaction, and thus provided a measurement strictly linked to isospin-dependent antikaon-nucleon scattering lengths. To fully disentangle the iso-scalar and iso-vector scattering lengths, the measurement of kaonic deuterium is necessary as well. The SIDDHARTA-2 experiment is now taking data at the DAFNE collider with the aim to fulfill the need of this measurement, and therefore provide important information to the various phenomenological models on low-energy strong interactions with strangeness. The SIDDHARTA-2 Collaboration is also exploring the possibility to perform future kaonic atoms experiments, developing X-ray detector systems beyond the current stateof-art. These measurements are crucial for a deeper understanding of the kaon interactions with nuclei and for solving the kaon mass ''puzzle''.
First measurement of kaonic helium-4 M-series transitions
F. Sgaramella, D. Sirghi, L. Abbene, F. Artibani, M. Bazzi, D. Bosnar, M. Bragadireanu, A. Buttacavoli, M. Cargnelli, M. Carminati, A. Clozza, F. Clozza, G. Deda, R. Del Grande, L. De Paolis, K. Dulski, 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. Niedzwiecki, H. Ohnishi, K. Piscicchia, F. Principato, A. Scordo, M. Silarski, F. Sirghi, M. Skurzok, A. Spallone, K. Toho, M. Tuchler, O. Vazquez Doce, C. Yoshida, J. Zmeskal, C. Curceanu

abstract
In this paper we present the results of a new kaonic helium-4 measurement with a 1.37 g/l gaseous target by the SIDDHARTA-2 experiment at the DAFNE collider. We measured, for the first time, the energies and yields of three transitions belonging to the Mseries. Moreover, we improved by a factor about three, the statistical precision of the 2p level energy shift and width induced by the strong interaction, obtaining the most precise measurement for gaseous kaonic helium, and measured the yield of the L_alpha transition at the employed density, providing a new experimental input to investigate the density dependence of kaonic atoms transitions yield.
CdZnTe detectors tested at the DAFNE collider for future kaonic atoms measurements
A. Scordo, L. Abbene, F. Artibani, M. Bazzi, M. Bettelli, D. Bosnar, G. Borghi, M. Bragadireanu, A. Buttacavoli, M. Cargnelli, M. Carminati, A. Clozza, F. Clozza, L. De Paolis, G. Deda, R. Del Grande, L. Fabbietti, C. Fiorini, I. Friščić, C. Guaraldo, M. Iliescu, M. Iwasaki, A. Khreptak, S. Manti, J. Marton, P. Moskal, F. Napolitano, S. Niedźwiecki, H. Ohnishi, K. Piscicchia, F. Principato, Y. Sada, F. Sgaramella, H. Shi, M. Silarski, D. L. Sirghi, F. Sirghi, M. Skurzok, A. Spallone, K. Toho, M. Tüchler, C. Yoshida, A. Zappettini, J. Zmeskal, C. Curceanu

abstract
The SIDDHARTA-2 collaboration at the INFN Laboratories of Frascati (LNF) aims to perform groundbreaking measurements on kaonic atoms. In parallel and beyond the ongoing kaonic deuterium, presently running on the DAFNE collider at LNF, we plan to install additional detectors to perform further kaonic atoms' studies, taking advantage of the unique low energy and low momentum spread K- beam delivered by the at-rest decay of the phi meson. CdZnTe devices are ideal for detecting transitions toward both the upper and lower levels of intermediate-mass kaonic atoms, like kaonic carbon and aluminium, which have an important impact on the strangeness sector of nuclear physics. We present the results obtained in a set of preliminary tests conducted on DAFNE, in view of measurements foreseen in 2024, with the twofold aim to tune the timing window required to reject the extremely high electromagnetic background, and to quantify the readout electronics saturation effect due to the high rate, when placed close to the Interaction Region (IR). In the first test we used commercial devices and electronics, while for the second one both were customized at the IMEM-CNR of Parma and the University of Palermo. The results confirmed the possibility of finding and matching a proper timing window where to identify the signal events and proved better performances, in terms of energy resolution, of the custom system. In both cases, strong saturation effects were confirmed, accounting for a loss of almost 90% of the events, which will be overcome by a dedicated shielding structure foreseen for the final experimental setup.
Characterization of the SIDDHARTA-2 Setup via the Kaonic Helium Measurement
F. Sgaramella, A. Clozza, L. Abbene, F. Artibani, M. Bazzi, G. Borghi, M. Bragadireanu, A. Buttacavoli, M. Cargnelli, M. Carminati, G. Deda, R. Del Grande, L. De Paolis, K. Dulski, C. Fiorini, C. Guaraldo, M. Iliescu, M. Iwasaki, A. Khreptak, S. Manti, J. Marton, M. Miliucci, P. Moskal, F. Napolitano, S. Niedzwiecki, H. Ohnishi, K. Piscicchia, F. Principato, A. Scordo, M. Silarski, D. Sirghi, F. Sirghi, M. Skurzok, A. Spallone, K. Toho, M. Tuchler, J. Zmeskal, C. Curceanu

abstract
The aim of the SIDDHARTA-2 experiment is to perform the first measurement ever of the width and shift induced by the strong interaction to the 2????->1????
energy transition of kaonic deuterium. This ambitious goal implies a challenging task due to the very low X-ray yield of kaonic deuterium, which is why an accurate and thorough characterization of the experimental apparatus is mandatory before starting the data-taking campaign. Helium-4 is an excellent candidate for this characterization since it exhibits a high yield in particular for the 3????->2????
transition, roughly 100 times greater than that of the kaonic deuterium. The ultimate goal of the work reported in this paper is to study the performances of the full experimental setup in view of the kaonic deuterium measurement. This is carried out by measuring the values of the shift and the width for the 3?????2????
energy transition of kaonic helium-4, induced by the strong interaction. The values obtained for these quantities, for a total integrated luminosity of ~31/pb, are epsilon_2????=2.0+-1.2(stat)+-1.5(syst)eV
and Gamma_2????=1.9+-5.7(stat)+-0.7(syst)eV. The results, compared to the value of the shift measured by the SIDDHARTA experiment epsilon_2????=0+-6(stat)+-2(syst)eV, show a net enhancement of the resolution of the apparatus, providing strong evidence of the potential to perform the challenging measurement of the kaonic deuterium.
The SIDDHARTA-2 Veto-2 system for X-ray spectroscopy of kaonic atoms at DAFNE
M. Tüchler, C. Amsler, M. Bazzi, D. Bosnar, M. Bragadireanu, M. Cargnelli, M. Carminati, A. Clozza, G. Deda, R. Del Grande, L. De Paolis, K. Dulski, L. Fabbietti, C. Fiorini, I. Friščić, C. Guaraldo, M. Iliescu, M. Iwasaki, A. Khreptak, S. Manti, J. Marton1, M. Miliucci, P. Moskal, F. Napolitano, S. Niedźwiecki, H. Ohnishi, K. Piscicchia, Y. Sada, A. Scordo, F. Sgaramella, H. Shi, M. Silarski, D. Sirghi, F. Sirghi, M. Skurzok, A. Spallone, K. Toho, O. Vazquez Doce, E. Widmann, C. Yoshida, J. Zmeskal and C. Curceanu

abstract
The Veto-2 is a fundamental component of a multiple-stage veto system for the SIDDHARTA-2 experiment installed at the DAFNE collider at INFN-LNF in Italy. It was developed to improve the signal-to-background ratio for the challenging measurement of X-ray transitions to the fundamental level in kaonic deuterium. Its purpose is the suppression of hadronic background in the form of Minimum Ionizing Particles by using the topological correlation between signals in the X-ray and Veto-2 detectors. The Veto-2 system consists of a barrel of plastic scintillators read out by Silicon Photomultipliers. The system performed its first successful test run within the apparatus with a helium-4 target in 2022. The efficiency of the Veto-2 was determined and found to be 0.62 +- 0.01. The Veto-2 improved the signal-to-background ratio for the kaonic helium-4 L_alpha measurement by about 16%, which is crucial due to the low expected X-ray yield of kaonic deuterium.
First Simultaneous K-p -> Sigma0 pi0, 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.
Kaonic atoms at the DAFNE collider: a strangeness adventure
C. Curceanu, L. Abbene, C. Amsler, M. Bazzi, M. Bettelli, G. Borghi, D. Bosnar, M. Bragadireanu, A. Buttacavoli, M. Cargnelli, M. Carminati, A. Clozza, G. Deda, R. Del Grande, L. De Paolis, K. Dulski, C. Fiorini, I. Friscic, C. Guaraldo, M. Iliescu, M. Iwasaki, A. Khreptak, S. Manti, J. Marton, M. Miliucci, P. Moskal, F. Napolitano, S. Niedzwiecki, H. Ohnishi, K. Piscicchia, F. Principato, Y. Sada, A. Scordo, F. Sgaramella, H. Shi, M. Silarski, D. L. Sirghi, F. Sirghi, M. Skurzok, A. Spallone, K. Toho, M. Tuchler, O. Vazquez Doce, C. Yoshida, A. Zappettini, J. Zmeskal

abstract
Kaonic atoms are an extremely efficient tool to investigate the strong interaction at the low energy Frontier, since they provide direct access to the K?N interaction at threshold, eliminating the necessity for extrapolation, unlike in the case of scattering experiments. During the 1970s and 1980s, extensive studies were performed on kaonic atoms spanning across a broad spectrum of elements in the periodic table, ranging from lithium to uranium. These measurements provided inputs and constraints for the theoretical description of the antikaon-nuclei interaction potential. Nevertheless, the existing data suffer from significant experimental uncertainties, and numerous measurements have been found to be inconsistent with more recent measurements that utilize advanced detector technology. Furthermore, there remain numerous transitions of kaonic atoms that have yet to be measured. For these reasons, a new era of kaonic atoms studies is mandatory. The DA?NE electron-positron collider at the INFN Laboratory of Frascati (INFN-LNF) stands out as a unique source of low-energy kaons, having been utilized by Collaborations such as DEAR, SIDDHARTA, and AMADEUS for groundbreaking measurements of kaonic atoms and kaon-nuclei interactions. Presently, the SIDDHARTA-2 experiment is installed at DA?NE, aiming to perform the first-ever measurement of the 2p ? 1s x-ray transition in kaonic deuterium, a crucial step towards determining the isospin-dependent antikaon-nucleon scattering lengths. Based on the experience gained with the SIDDHARTA experiment, which performed the most precise measurement of the kaonic hydrogen 2p ? 1s x-ray transition, the SIDDHARTA-2 setup is now fully equipped for the challenging kaonic deuterium measurement. In this paper, we present a comprehensive description of the SIDDHARTA-2 setup and of the first kaonic atoms measurements performed during the commissioning phase of the DA?NE collider. We also outline a proposal for future measurements of kaonic atoms at DA?NE beyond SIDDHARTA-2, which is intended to stimulate discussions within the broad scientific community performing research, directly or indirectly, related to this field.
Potentialities of CdZnTe Quasi-Hemispherical Detectors for Hard X-ray Spectroscopy of Kaonic Atoms at the DAFNE Collider
L. Abbene, A. Buttacavoli, F. Principato, G. Gerardi, M. Bettelli, A. Zappettini, M. Bazzi, M. Bragadireanu, M. Cargnelli, M. Carminati, A. Clozza, G. Deda, R. Del Grande, L. De Paolis, L. Fabbietti, C. Fiorini, C. Guaraldo, M. Iliescu, M. Iwasaki, A. Khreptak, S. Manti, J. Marton, M. Miliucci, P. Moskal, F. Napolitano, S. Niedzwiecki, H. Ohnishi, K. Piscicchia, Y. Sada, F. Sgaramella, H. Shi, M. Silarski, D. L. Sirghi, F. Sirghi, M. Skurzok, A. Spallone, K. Toho, M. Tuchler, O. Vazquez Doce, C. Yoshida, J. Zmeskal, A. Scordo, C. Curceanu

abstract
Kaonic atom X-ray spectroscopy is a consolidated technique for investigations on the physics of strong kaon?nucleus/nucleon interaction. Several experiments have been conducted regarding the measurement of soft X-ray emission (<20 keV) from light kaonic atoms (hydrogen, deuterium, and helium). Currently, there have been new research activities within the framework of the SIDDHARTA-2 experiment and EXCALIBUR proposal focusing on performing precise and accurate measurements of hard X-rays (>20 keV) from intermediate kaonic atoms (carbon, aluminum, and sulfur). In this context, we investigated cadmium?zinc?telluride (CdZnTe or CZT) detectors, which have recently demonstrated high-resolution capabilities for hard X-ray and gamma-ray detection. A demonstrator prototype based on a new cadmium?zinc?telluride quasi-hemispherical detector and custom digital pulse processing electronics was developed. The detector covered a detection area of 1 cm2 with a single readout channel and interesting room-temperature performance with energy resolution of 4.4% (2.6 keV), 3% (3.7 keV), and 1.4% (9.3 keV) FWHM at 59.5, 122.1, and 662 keV, respectively. The results from X-ray measurements at the DAFNE collider at the INFN National Laboratories of Frascati (Italy) are also presented with particular attention to the effects and rejection of electromagnetic and hadronic background.
A review of the low-energy K--nucleus/nuclei interactions with light nuclei AMADEUS investigations
M. Skurzok, M. Cargnelli, R. Del Grande, L. Fabbietti, C. Guaraldo, J. Marton, P. Moskal, K. Piscicchia, A. Scordo, M. Silarski, D. L. Sirghi, O. Vazquez Doce, J. Zmeskal, S. Wycech, P. Branchini, E. Czerwinski, X. Kang, G. Mandaglio, M. Martini, A. Selce and C. Curceanu

abstract
The AMADEUS Collaboration conducts research aimed to experimentally investigate the low-energy K- hadronic interactions with light nuclei like hydrogen, helium, and carbon, in order to provide new constraints to the antikaon-nucleon strong interaction studies in the non-perturbative quantum chromodynamics regime. K- nuclear absorption, both at-rest and in-flight, are explored using the unique low-momentum and monochromatic kaon beam from the DAFNE collider interacting with the KLOE detector components, a detector characterized by high acceptance and excellent position and momentum resolutions. This paper presents an overview of the AMADEUS results.
The KAMEO proposal: Investigation of the E2 nuclear resonance effects in kaonic atoms
L. De Paolis on behalf of M. Bazzi, D. Bosnar, M. Bragadireanu, M. Cargnelli, M. Carminati, A. Clozza, G. Deda, R. Del Grande, K. Dulski, C. Fiorini, I. Frišči`c, C. Guaraldo, M. Iliescu, M. Iwasaki, A. Khreptak, S. Manti, J. Marton, M. Miliucci, P. Moskal, F. Napolitano, S. Nied`zwiecki, O. Ohnishi, K. Piscicchia, Y. Sada, A. Scordo, F. Sgaramella, H. Shi, M. Silarski, D. L. Sirghi, F. Sirghi, M. Skurzok, S. Wycech, A. Spallone, K. Toho, M. Tüchler, C. Yoshida, J. Zmeskal, C. Curceanu

abstract
The E2 nuclear resonance effect is a phenomenon that occurs whenthe energy of an atomic de-excitation state closely matches that of a nuclear excita-tion state, resulting in the attenuation of certain atomic X-ray lines in the resonantisotope target. The study of this effect in kaonic atoms can provide important insightinto the mechanisms of the strong kaon-nucleus interaction. In 1975, Goldfrey, Lum,and Wiegand at Lawrence Berkeley Laboratory observed the effect in9842Mo, but theydid not have enough data to reach a conclusive result. The E2 nuclear resonanceeffect is expected to occur in four kaonic molybdenum isotopes (9442Mo,9642Mo,9842Mo,and10042Mo) with similar energy values. The KAMEO (Kaonic Atoms MeasuringNuclear Resonance Effects Observables) proposal plans to study this effect in theseisotopes at the DA?NE ? factory during the SIDDHARTA-2 experiment. KAMEOwill use four solid strip targets, each enriched with a different molybdenum isotope,and expose them to negatively charged kaons produced by ? meson decays. TheX-ray transition measurements will be performed using a high-purity germaniumdetector, and an additional solid strip target of non-resonant9242Mo isotope will beexposed and used as a reference for standard non-resonant transitions.
New opportunities for kaonic atoms measurements from CdZnTe detectors
L. Abbene, M. Bettelli, A. Buttacavoli, F. Principato, A. Zappettini, 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, I. Friscic, C. Guaraldo, M. Iliescu, M. Iwasaki, A. Khreptak, 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. Tuchler, O. Vazquez Doce, C. Yoshida, J. Zmeskal, A. Scordo and C. Curceanu

abstract
We present the tests performed by the SIDDHARTA-2 collaboration at the DAFNE collider with
a quasi-hemispherical CdZnTe detector. The very good room-temperature energy resolution and efficiency
in a wide energy range show that this detector technology is ideal for studying radiative transitions in
intermediate and heavy mass kaonic atoms. The CdZnTe detector was installed for the first time in an
accelerator environment to perform tests on the background rejection capabilities, which were achieved by
exploiting the SIDDHARTA-2 Luminosity Monitor. A spectrum with an 241Am source has been acquired,
with beams circulating in the main rings, and peak resolutions of 6% at 60 keV and of 2.2% at 511 keV
have been achieved. The background suppression factor, which turned out to be of the order of ~10^5?6,
opens the possibility to plan for future kaonic atom measurements with CdZnTe detectors.
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.
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.
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.
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.
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.
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.
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.
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.
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
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.
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.
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.
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.
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.
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.))%.
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.
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
Kaonic Atoms to Investigate Global Symmetry Breaking
C. Curceanu, C. Guaraldo, D. Sirghi, A. Amirkhani, A. Baniahmad , M. Bazzi, G. Bellotti, D. Bosnar, 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. Tuchler, 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 (KN) 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.
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.
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
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.
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.
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.
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.
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.
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.
Tests of New CZT detectors at DAFNE collider for Kaonic Atoms Measurements
F. Artibani, L. Abbene, M. Bazzi, G. Borghi, D. Bosnar, M. Bragadireanu, A. Buttacavoli, M. Cargnelli, M. Carminati, A. Clozza, F. Clozza, L. De Paolis, R. Del Grande, K. Dulski, C. Fiorini, I. Friščić, C. Guaraldo, M. Iliescu, M. Iwasaki, A. Khreptak, S. Manti, J. Marton, P. Moskal, F. Napolitano, S. Niedźwiecki, H. Ohnishi, K. Piscicchia, F. Principato, A. Scordo, F. Sgaramella, M. Silarski, D. L. Sirghi, F. C. Sirghi, M. Skurzok, A. Spallone, K. Toho, L.G. Toscano, M. Tuchler, J. Zmeskal and C. Curceanu
published in: PoS DISCRETE2024, 031 (2024)
Kaonic atom spectroscopy provides key observables for investigating low-energy strong interactions in strange systems. In this paper, we present an overview of the SIDDHARTA-2 collaboration's activities in the field of kaonic atoms, with a particular focus on the development of a new Cadmium-Zinc-Telluride (CZT) detector system for the study of intermediate-mass kaonic atoms.
This novel detection system, applied for the first time in fundamental physics research at a collider, is designed to extend the energy range accessible in kaonic atom spectroscopy. We report on the characteristics of the detector and the results of test measurements conducted at the DAFNE collider between 2022 and 2024.The tests demonstrated that the detector's energy resolution, efficient background rejection, and good timing performance make it ideal for performing kaonic atom measurements.
The ultimate goal of these developments is to refine our understanding of kaon-multinucleon low-energy strong interactions by providing high-precision measurements of intermediate-mass kaonic atoms.
New Opportunities in Kaonic Atoms Spectroscopy With Novel CZT Detector
F. Artibani, L. Abbene, M. Bettelli, A. Buttacavoli, F. Principato, A. Zappettini, M. Bazzi, G. Borghi, D. Bosnar, M. Bragadireanu, M. Cargnelli, M. Carminati, A. Clozza, F. Clozza, L. De Paolis, R. Del Grande, K. Dulski, L. Fabbietti, C. Fiorini, I. Friščić, C. Guaraldo, M. Iliescu, M. Iwasaki, A. Khreptak, S. Manti, J. Marton, P. Moskal, F. Napolitano, S. Niedźwiecki, H. Ohnishi, K. Piscicchia, Y. Sada, F. Sgaramella, D. L. Sirghi, F. Sirghi, M. Skurzok, M. Silarski, A. Spallone, K. Toho, L. Toscano, M. Tuchler, J. Zmeskal, C. Curceanu, A. Scordo
published in: Frascati Physics Series 76 (2024) 96
Kaonic atoms spectroscopy provides important observables for low-energy strong interactions in strange systems studies. In this paper, an overview of the SIDDHARTA-2 activities in kaonic atoms field is presented. Particular attention is given to the development of the new cadmium-zinc-telluride detection systems to measure intermediate-mass kaonic atoms. The characteristics of the detector, the results of the two first test measurements in DAFNE, and some of the physics goals are presented.
Kaonic atoms studies with SIDDHARTA-2 at DAFNE
K. Toho, L. Abbene, F. Artibani, M. Bazzi, G. Borghi, M. Bragadireanu, A. Buttacavoli, M. Cargnelli, M. Carminati, A. Clozza, F. Clozza, L. De Paolis, R. Del Grande, K. Dulski, C. Fiorini, I. Friščić, C. Guaraldo, M. Iliescu, M. Iwasaki, A. Khreptak, S. Manti, J. Marton, P. Moskal, F. Napolitano, S. Niedźwiecki, H. Ohnishi, K. Piscicchia, F. Principato, A. Scordo, F. Sgaramella, M. Silarski, D. L. Sirghi, F. Sirghi, M. Skurzok, A. Spallone, L. Toscano, M. Tuchler, J. Zmeskal, C. Curceanu
published in: Frascati Physics Series 76 (2024) 110
The SIDDHARTA-2 experiment advances the study of kaonic atoms, focusing on kaonic deuterium
and other kaonic atoms, such as neon, to explore low-energy Quantum Chromodynamics (QCD). Utilizing
Silicon Drift Detectors and sophisticated veto systems, the experiment conducts high-precision X-ray
spectroscopy to measure strong interaction-induced shifts and broadenings of atomic energy levels. This
enables investigations of both electromagnetic and non-perturbative QCD effects, with high-n transitions
facilitating precision tests of Quantum Electrodynamics (QED) and lower-level transitions providing
insights into antikaon-nuclei strong interaction. Preliminary observation
A new measurement of the kaonic helium L-lineswith SIDDHARTA-2 at DAFNE
F. Clozza, L. Abbene, F. Artibani, M. Bazzi, G. Borghi, D. Bosnar, M. Bragadireanu, A. Buttacavoli, M. Cargnelli, M. Carminati, A. Clozza, G. Deda, L. De Paolis, R. Del Grande, K. Dulski, C. Fiorini, I. Friščić, C. Guaraldo, M. Iliescu, M. Iwasaki, A. Khreptak, S. Manti, J. Marton, P. Moskal, F. Napolitano, S. Niedźwiecki, H. Ohnishi, K. Piscicchia, F. Principato, A. Scordo, F. Sgaramella, M. Silarski, D. L. Sirghi, F. Sirghi, M. Skurzok, A. Spallone, K. Toho, M. Tuchler, J. Zmeskal, C. Curceanu
published in: Frascati Physics Series 76 (2024) 103
The ultimate goal of the SIDDHARTA-2 experiment at the LNF-INFN is to perform the first ever
measurement, via X-ray spectroscopy, of the width and shift induced by the strong interaction to the
2p -> 1s energy transition of kaonic deuterium. Such a measurement has not been performed yet due
to its high difficulty level; in fact, this transition exhibits an extremely low X-ray yield. For this reason,
before starting the kaonic deuterium data taking campaign, an accurate and thorough characterisation
of the experimental apparatus is of primary importance to gauge its performance. To finalize such a task
the best candidate is Helium-4, since the 3d ->2p transition of kaonic helium-4 exhibits a much higher
yield of X-rays. This work reports the results of the characterisation of the SIDDHARTA-2 apparatus in
preparation for the kaonic deuterium measurement. This is done by measuring the shift and width for
the 3d ? 2p transition of kaonic helium-4. The measured values are epsilon_2p = 2.0 pm 1.2(stat) pm 1.5(syst) eV
and Gamma_2p = 1.9 pm 5.7(stat) pm 0.7(syst) eV. The result shows a net enhancement of the performance
of the apparatus when compared to the previous measurement done by the SIDDHARTA experiment
epsilon_2p = 0 pm 6(stat) pm 2(syst) eV, thus providing strong evidence of the potential to perform the kaonic
deuterium measurement.
Kaonic helium-4 L-series yield measurement at 2.25 g/l density by SIDDHARTA-2 at DAFNE
F. Sgaramella, M. Bazzi, A. Clozza, C. Curceanu, L. De Paolis, K. Dulski, C. Guaraldo, M. Iliescu, A. Khreptak, S. Manti, F. Napolitano, A. Scordo, F. Sirghi, A. Spallone, M. Miliucci, F. Artibani, F. Clozza, M. Cargnelli, J. Marton, M. Tüchler, J. Zmeskal, L. Abbene, A. Buttacavoli, F. Principato, D. Bosnar, I. Friščić, M. Bragadireanu, G. Borghi, M. Carminati, G. Deda, C. Fiorini, R. Del Grande, M. Iwasaki, P. Moskal, S. Niedźwiecki, M. Silarski, M. Skurzok, H. Ohnishi, K. Toho, C. Yoshida, D. Sirghi, K. Piscicchia
published in: Acta Phys. Pol. B Proc. Suppl. 17 (2024) 1-A8
This article presents the results of the kaonic helium-4 measurement conducted by the SIDDHARTA-2 experiment, aiming to provide crucial insights into the low-energy strong interaction in the strangeness sector. High-precision X-ray spectroscopy is used to examine the interaction between negatively charged kaons and nuclei in atomic systems. The SIDDHARTA-2setup was optimized through the kaonic helium-4 measurement in preparation for the challenging kaonic deuterium measurement. The kaonic helium-4 measurement at a new density of 2.25 g/l is reported, providing the absolute and relative yields for the L-series transitions, which are essential data for understanding kaonic atom cascade processes.
The measurement of the E2 nuclear resonance effects in kaonic atoms at DA?NE: The KAMEO proposal
L. De Paolis, L. Abbene, M. Bazzi, M. Bettelli, G. Borghi, D. Bosnar, M. Bragadireanu, A. Buttacavoli, M. Cargnelli, M. Carminati, A. Clozza, G. Deda, R. Del Grande, K. Dulski, C. Fiorini, I. Friscic, C. Guaraldo, M. Iliescu, M. Iwasaki, A. Khreptak, S. Manti, J. Marton, M. Miliucci, P. Moskal, F. Napolitano, S. Niedźwiecki, J. Obertova, O. Ohnishi, K. Piscicchia, F. Principato, Y. Sada, A. Scordo, F. Sgaramella, M. Silarski, D.L. Sirghi, F. Sirghi, M. Skurzok, S. Wycech, A. Spallone, K. Toho, M. Tüchler, C. Yoshida, A. Zappettini, J. Zmeskal, C. Curceanu
published in: EPJ Web of Conferences 291 (2024) 05003
KAMEO (Kaonic Atoms Measuring Nuclear Resonance Effects Ob-servables) is a proposal for an experiment aiming to perform the first consistent measurement of the E2 nuclear resonance effects in kaonic molybdenum A=94,96,98,100 isotopes. The E2 nuclear resonance mixes atomic states, due to the electrical quadrupole excitation of nuclear rotational states. It occurs in atoms having the energy of a nuclear excitation state closely matching an atomic de-excitation state energy, and affects the rates of X-ray atomic transitions matching the energy of the resonance. The measurement E2 nuclear resonance effect in KMO isotopes allows the study of the strong kaon-nucleus interaction in a rotational excited nuclear state. Moreover, the effect enables the K- to access an inner atomic level not easily reachable by the kaon normal cascade, due to the nuclear absorption. The KAMEO proposed apparatus consists of 4 enriched Mo A=94,96,98,100 isotope strips, exposed to the kaons produced by the DA?NE collider, for kaonic atoms formation, with a high-purity germanium detector, cooled with liquid nitrogen, used to measure the X-ray atomic transitions. The DA?NE collider is located at the National Laboratories of Frascati (LNF-INFN), in Italy. It is already suited for kaonic atoms measurement by the SIDDHARTA-2 collaboration.
Kaonic atoms with SIDDHARTA-2 at the DAFNE collider
F. Sirghi, L. Abbene, M. Bazzi, D. Bosnar, M. Bragadireanu, A. Buttacavoli, M. Cargnelli, M. Carminati, A. Clozza, G. Deda, R. Del Grande, K. Dulski, L. De Paolis, C. Fiorini, I. Friscic, C. Guaraldo, M. Iliescu, M. Iwasaki, A. Khreptak, S. Manti, J. Marton, M. Miliucci, P. Moskal, F. Napolitano, F. Sgaramella, S. Niedźwiecki, O. Ohnishi, K. Piscicchia, Y. Sada, A. Scordo, M. Silarski, D.L. Sirghi, M. Skurzok, A. Spallone, S. Wycech, K. Toho, M. Tüchler, C. Yoshida, J. Zmeskal, C. Curceanu
published in: EPJ Web of Conferences 291 (2024) 01008
. The most important information still missing in the field of the low-energy antikaon-nucleon interactions studies is the experimental determination of the hadronic energy shift and width of kaonic deuterium.
This measurement will be performed by the SIDDHARTA-2 experiment, installed at the DA?NE collider
and presently in data taking campaign. The precise measurement of the shift and width of the 1s level with
respect to the purely electromagnetic calculated values, generated by the presence of the strong interaction,
through the measurement of the X-ray transitions to this level, in kaonic hydrogen, was performed by the SIDDHARTA collaboration, the kaonic deuterium is underway by SIDDHARTA-2. These measurement will allow
the first precise experimental extraction of the isospin dependent antikaon-nucleon scattering lengths, fundamental quantities for understanding low-energy QCD in the strangeness sector. The experimental challenge of
the kaonic deuterium measurement is the very small X-rays yield, the even larger width (compared to kaonic hydrogen), and the difficulty to perform X-rays spectroscopy with weak signals in the high radiation environment
of DA?NE. It was, therefore, crucial to develop a new apparatus involving large-area X-rays detector system,
to optimize the signal and to control and by improve the signal-to-background ratio by gaining in solid angle,
increasing the timing capability, and as well implementing additional charge particle tracking veto systems.
SIDDHARTA-2 veto system design and performance for kaonic atoms studies at DAFNE
F. Sgaramella, M. Bazzi, D. Bosnar, M. Bragadireanu, M. Cargnelli, M. Carminati, A. Clozza, G. Deda, R. Del Grande, K. Dulski, L. De Paolis, 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. Ohnishi, K. Piscicchia, Y. Sada, A. Scordo, M. Silarski, D. Sirghi, F. Sirghi, M. Skurzok, A. Spallone, K. Toho, M. Tuchler, C. Yoshida, J. Zmeskal, C. Curceanu
published in: EPJ Web Conf. 290 (2023) 06005
Light kaonic atoms spectroscopy provides a unique approach to study the low-energy strong interaction in the strangeness sector. Precise measurements of X-ray emission from light kaonic atoms provide valuable information on kaon-nucleus interaction at threshold without the need for extrapolation as required in scattering experiments. The SIDDHARTA-2 experiment at the DA?NE collider of INFN-LNF is now poised to perform the challenging measurements of the K?- d 2p -> 1s transition to extract the isospin-dependent antikaonnucleon scattering lengths. To achieve this goal, the background reduction is a crucial factor. This paper provides an overview of the SIDDHARTA-2 Veto-1 system, which uses scintillators outside the vacuum chamber to detect charged particles produced by K? absorption by the nucleus. The arrival time of these particles is correlated with the position where the kaonic atom has been created inside the setup, allowing for the rejection of kaons stopped outside the target cell, which is a critical component for reducing the background and improve the accuracy of the measurement.
Investigating the E2 Nuclear Resonance Effects in Kaonic Atoms: The KAMEO Proposal
L. De Paolis, D. Bosnar, M. Bragadireanu, M. Cargnelli, M. Carminati, A. Clozza, G. Deda, R. Del Grande, K. Dulski, C. Fiorini, I. Friscic, C. Guaraldo, M. Iliescu, M. Iwasaki, A. Khreptak, S. Manti, J. Marton, M. Miliucci, P. Moskal, F. Napolitano, S. Niedźwiecki, O. Ohnishi, K. Piscicchia, Y. Sada, A. Scordo, F. Sgaramella, M. Silarski, D.L. Sirghi, F. Sirghi, M. Skurzok, S. Wycech, A. Spallone, K. Toho, M. Tüchler, C. Yoshida, J. Zmeskal, C. Curceanu
published in: EPJ Web of Conferences 290 (2023) 06003
The E2 nuclear resonance effect in kaonic atoms occurs when the energy of atomic de-excitation closely matches the energy of nuclear excitation, leading to the attenuation of some X-ray lines in the resonant isotope target. This phenomenon provides crucial information on the strong interaction between kaons and nuclei. The only nuclear E2 resonance effect observed so far was in the K? ?9842Mo isotope, measured by G. L. Goldfrey, G-K. Lum, and C. E. Wiegand at Lawrence Berkeley Laboratory in 1975. However, the 25 hours of data taking were not sufficient to yield conclusive results. In four kaonic Molybdenum isotopes (9442Mo, 9642Mo, 9842and Mo, and 10042Mo), the nuclear E2 resonance effect is expected to occur at the same transition with similar energy values. To investigate this, the KAMEO (Kaonic Atoms Measuring Nuclear Resonance Effects Observables) experiment plans to conduct research on kaonic Molybdenum isotopes at the DA?NE e+e? collider during the SIDDHARTA-2 experiment. The experimental strategy involves exposing four solid strip targets, each enriched with one Molybdenum isotope, to negatively charged kaons and using a germanium detector to measure X-ray transitions. In addition, a non-resonant 9242Mo isotope solid strip target will be used as a reference for standard non-resonant transitions.
Investigating the E2 nuclear resonance effect in kaonic atoms
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, S. Wycech, A. Spallone, K. Toho, M. Tüchler, O. Vazquez Doce, C. Yoshida, J. Zmeskal and C. Curceanu
published in: J. Phys.: Conf. Ser. 2446 (2023) 012038
The nuclear E2 resonance effect occurs when an atomic de-excitation energy is closely matched by a nuclear excitation energy. It produces an attenuation of some of the atomic X-ray lines in the resonant isotope target. Investigating the nuclear E2 resonance effect in kaonic atoms, important information about kaon-nucleus strong interaction can be provided. The only ${K}^{-}{-}_{42}^{98}mathrm{Mo}$ nuclear resonance effect was measured by G. L. Goldfrey, G- K. Lum and C. E. Wiegand at Lawrence Berkeley Laboratory, in 1975. The nuclear E2 resonance effect was observed in 25 hours of data taking, not enough to provide a conclusive result. In four kaonic Molybdenum isotopes (${}_{42}^{94}mathrm{Mo}$, ${}_{42}^{96}mathrm{Mo}$, ${}_{42}^{98}mathrm{Mo}$ and ${}_{42}^{100}mathrm{Mo}$), the nuclear E2 resonance effect is expected at the same transition, with similar energy values. The KAMEO (Kaonic Atoms Measuring nuclear resonance Effects Observables) experiment plans to study the E2 nuclear resonance effect in kaonic Molybdenum isotopes at the DA?NE e+e? collider, during the SIDDHARTA-2 experiment. The experimental strategy consists of exposing four solid strip targets, each enriched with one Molybdenum isotope, to negatively charged kaons, using a germanium detector for X-ray transition measurements. A further exposure of a non-resonant ${}_{42}^{92}mathrm{Mo}$ isotope solid strip target will be used as reference for standard non-resonant transitions.
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
published in: EPJ Web Conf. 279 (2023) 11019
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 about 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 pi0 and Lambda p final states is presented.
Kaonic atoms measurements with SIDDHARTA-2
F. Sgaramella, M. Bazzi, D. Bosnar, M. Bragadireanu, M. Cargnelli, M. Carminati, A. Clozza, G. Deda, R. Del Grande, L. De Paolis, K. Dulski, L. Fabbietti, C. Fiorini, I. Friščić, C. Guaraldo, M. Iliescu, M. Iwasaki, A. Khreptak, S. Manti, J. Marton, M. Miliucci, P. Moskal, F. Napolitano, S. Niedźwiecki, H. Ohnishi, K. Piscicchia, Y. Sada, A. Scordo, H. Shi, M. Silarski, D. Sirghi, F. Sirghi, M .Skurzok, A. Spallone, K. Toho, M. Tüchler, C. Yoshida, J. Zmeskal, C. Curceanu
published in: J. Phys.: Conf. Ser. 2446 (2023) 012023
The SIDDHARTA-2 collaboration is aiming to perform the challenging measurement of kaonic deuterium X-ray transitions to the ground state. This will allow to extract the isospin-dependent antikaon-nucleon scattering lengths, providing input to the theory of Quantum Chromodynamics (QCD) in the non-perturbative regime with strangeness. This work describes the SIDDHARTA-2 experimental apparatus and presents the results obtained during the commissioning phase realized with kaonic helium measurements. In particular, the first observation of the kaonic helium transitions to the 3s level (M-lines), reported in this work, represents a new source of information to study the kaonic helium cascade process and demonstrates the potential of the SIDDHARTA-2 apparatus, in the view of the ambitious kaonic deuterium measurement.
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
published in: PoS ICHEP2022 (2022) 1003
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.
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
published in: EPJ Web Conf. 270 (2022) 00028
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.
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
published in: Acta Phys. Polon. B Proc. Suppl. 15 (2022) 4-A1
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.
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
published in: PoS PANIC2021 (2022) 200
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.
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
published in: Suplemento de la Revista Mexicana de Fisica 30308081 (2022) 1
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.
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
published in: EPJ Web Conf. 262 (2022) 01016
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
published in: EPJ Web Conf. 262 (2022) 01006
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.
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
published in: EPJ Web Conf. 258 (2022) 07006
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.
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
published in: J. Phys. Conf. Ser. 1643 (2020) 012182
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.
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
published in: J. Phys. Conf. Ser. 1643 (2020) 012081
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.
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
published in: Springer Proc. Phys. 250 (2020) 403-407
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.
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
published in: Acta Phys. Polon. B Proc. Suppl. 14 (2021) 49
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
published in: J. Phys. Conf. Ser. 1526 (2020) 012023
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
published in: J. Phys. Conf. Ser. 1526 (2020) 012024
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.
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
published in: Springer Proc.Phys. 238 (2020) 937-941
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
published in: Springer Proc. Phys. 238 (2020) 965
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.
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
published in: SciPost Phys. Proc. 3 (2020) 039
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.
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
published in: JPS Conf. Proc. 26 (2019) 023011
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
published in: JPS Conf. Proc. 26 (2019) 023012
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.
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
published in: Springer Proc. Phys. 225 (2019) 191-195
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
published in: AIP Conf. Proc. 2130 (2019) 020021
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.
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
published in: EPJ Web Conf. 199 (2019) 01014
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
published in: EPJ Web Conf. 199 (2019) 03010
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
published in: EPJ Web Conf. 199 (2019) 03004
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.
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
published in: J. Phys. Conf. Ser. 1138 no.1 (2018) 012012
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
published in: J. Phys. Conf. Ser. 1138 no. 1 (2018) 012011
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, ...
published in: J. Phys. Conf. Ser. 1138 no.1 (2018) 012013
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.
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
published in: Acta Phys. Polon. Supp. 11 (2018) 609-616
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
published in: EPJ Web Conf. 181 (2018) 01004
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
published in: EPJ Web Conf. 182 (2018) 02035
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
published in: EPJ Web Conf. 181 (2018) 01005
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.
Low-energy antikaon-nuclei interactions studies by AMADEUS: from QCD with strangeness to neutron stars
K. Piscicchia,..., R. Del Grande, ..., P. Moskal
published in: EPJ Web Conf. 166 (2018) 00020
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
published in: EPJ Web Conf. 165 (2017) 01046
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.
Low-energy Antikaon-Nucleon Absorption Studies by AMADEUS
K. Piscicchia,..., R. Del Grande, ..., P. Moskal, ..., M. Silarski, ..., M. Skurzok, ...
published in: Acta Phys. Polon. Supp. 10 (2017) 1125
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.
Investigating the low-energy K- interactions in nuclear matter with AMADEUS
R. Del Grande, ...., P. Moskal, et al. (AMADEUS Collaboration)
published in: J. Phys. Conf. Ser. 841 (2017) no.1, 012023
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.
K- multi-nucleon absorption processes in hadronic interaction studies
R. Del Grande, ..., E. Czerwinski, ..., W. Krzemien, ..., P. Moskal, ..., M. Silarski, et al. (AMADEUS Collaboration)
published in: PoS BORMIO2016 (2016) 010
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.