Marian Smoluchowski
Institute of Physics

Jagiellonian University

Publications

ARTICLES CONFERENCE PROCEEDINGS

1. Development of correction techniques for a J-PET scanner
   M. Das, R. Bayerlein, S. Sharma, S. Parzych, S. Niedźwiecki, R. Badawi, E. Yitayew Beyene, N. Chug, C. Curceanu, E. Czerwiński, K. Valsan Eliyan, B. Głowa, A. Hubalewska-Dydejczyk, K. Kacprzak, T. Kaplanoglu, K. Kasperska, G. Korcyl, A. Khreptak, K. Kubat, D. Kumar, E. Lisowski, F. Lisowski, J. Mędrala-Sowa, S. Moyo, W. Mryka, M. Opalińska, P. Pandey, M. Rädler, M. Skurzok, A. Sowa-Staszczak, B. A. Spencer, P. Tanty, K. Tayefi Ardebili, A. Kunimmal Venadan, E. Stępień, P. Moskal
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   abstract

   Bio-Algorithms and Med-Systems 20 (2024)
   Objective: Positron Emission Tomography (PET) is a widely used medical imaging technique that allows for non-invasive imaging of metabolic processes. However, traditional PET scanners rely on costly inorganic scintillators, which limit their accessibility ? especially in light of emerging long axial field-of-view devices. The modular J-PET scanner, an innovative alternative, uses 50-cm long plastic scintillator strips, offering a cost-effective and modular solution. In this study, we develop and assess the PET data correction techniques required for quantitative image reconstruction. Methods: We present methods for attenuation correction, random coincidence correction using the Delayed Time Window (DTW) technique, and scatter correction based on Monte Carlo simulations. Phantom studies using the NEMA IQ phantom were performed to qualitatively evaluate these corrections. Results: The results demonstrate that our implemented corrections for attenuation, randoms, and scattered coincidences successfully improve the uniformity of tracer distribution in homogenous volumes and significantly reduce undesired activity in cold regions. Despite limitations in sensitivity and axial resolution, the applied correction techniques effectively enhance image quality, providing promising results for future applications. Conclusions: These findings highlight the potential of the modular J-PET system to offer affordable PET imaging and to pave the way towards a total-body PET scanner based on plastic scintillators. Future work will focus on quantitative validation and the implementation of these corrections for human subject imaging.
2. Feasibility studies of Dark Photon searches with the J-PET detector
   Justyna Mędrala-Sowa, Elena Perez del Rio, Wojciech Krzemień
   abstract

   Symposium on new trends in Nuclear and Medical Physics

1. Mirror Matter in Ortho-positronium Decay Searches Using the J-PET Detector
   J. Mędrala-Sowa, E. Perez del Rio, P. Moskal
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   published in: Acta Phys. Pol. B Proc. Suppl. 17 (2024) 7-A8
   Positronium (Ps), governed by Quantum Electrodynamics (QED), provides a rich domain for exploring fundamental physics. Monte Carlo simulations of its decay provide insights into various aspects of particle physics. The development of J-PET, an innovative tomography system at the Jagiellonian University using high-resolution scintillator detectors, facilitates interdisciplinary studies encompassing fundamental physics tests, medical research, and quantum entanglement measurements but also enhances our capacity to investigate positronium decays in pursuit of potential dark matter (DM) candidates, a lingering enigma within the current Standard Model (SM) framework. In our research, we employ the J-PET detector to study ortho-positronium (o-Ps) decays as a part of our ongoing quest for the discovery of DM. Our primary goal is to explore mirror matter, which seeks to restore parity invariance and is proposed as a candidate for the Universe?s DM. Our study aims to push the boundaries of precision measurement in the decay width of o-Ps to three gamma quanta, contributing to our understanding of the elusive nature of dark matter. The article presents the preliminary lifetime distribution of o-Ps as a search for mirror matter obtained from data collected during a portion of a long-term measurement conducted with the J-PET detector in 2020. The long-term aim of the study is to achieve 10^-6 lifetime sensitivity.
2. Feasibility studies of dark photon searches with the J-PET detector
   J. Mędrala-Sowa, E. Perez del Rio, W. Krzemień
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   published in: Acta Phys. Pol. B Proc. Suppl. 17 (2024) 1-A5
   The positronium, a bound state of electron and positron, is a unique system to perform highly precise tests, due to no hadronic background and precise Quantum Electrodynamics (QED) predictions. Being a system of lepton and antilepton, its properties are precisely described by QED in the Standard Model (SM). The final events topology can be simulated using Monte Carlo techniques. The J-PET detector is a multi-purpose, large acceptance system that is very well-suitable to the studies of positronium decay due to its excellent angular (1?) and timing resolutions. We present preliminary results on the feasibility of searching for Dark Matter (DM) candidates in the decay o-Ps -> invisible with the J-PET, which is wellsuited for the detection of positronium-decay products. Toy Monte Carlo simulations have been prepared to incorporate DM decay models to the oPs decay expectations in order to assess the detector capabilities to search for such an elusive component of our Universe.