W. Krzemień
A5019647611- Particle physics theoretical and experimental studies
- Quantum Chromodynamics and Particle Interactions
- High-Energy Particle Collisions Research
- Medical Imaging Techniques and Applications
- Radiation Detection and Scintillator Technologies
- Atomic and Subatomic Physics Research
- Neutrino Physics Research
- Particle Detector Development and Performance
- Dark Matter and Cosmic Phenomena
- Nuclear physics research studies
- Computational Physics and Python Applications
- Black Holes and Theoretical Physics
- Superconducting Materials and Applications
- Nuclear Physics and Applications
- Particle Accelerators and Free-Electron Lasers
- Quantum, superfluid, helium dynamics
- Muon and positron interactions and applications
- Radiation Therapy and Dosimetry
- Advanced MRI Techniques and Applications
- Stochastic processes and statistical mechanics
- Advanced Radiotherapy Techniques
- Cosmology and Gravitation Theories
- Noncommutative and Quantum Gravity Theories
- Advanced Data Storage Technologies
- Advanced X-ray and CT Imaging
Jagiellonian University
2013-2025
National Centre for Nuclear Research
2016-2025
European Organization for Nuclear Research
2016-2024
University of Groningen
2024
Theranostics (New Zealand)
2024
Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Frascati
2023
WSB University
2021
Poznan University of Medical Sciences
2021
University of Hradec Králové
2021
Charles University
2021
To study fundamental questions of hadron and nuclear physics in interactions antiprotons with nucleons nuclei, the universal PANDA detector will be built. Gluonic excitations, strange charm quarks nucleon structure studies performed unprecedented accuracy thereby allowing high-precision tests strong interaction. The proposed is a state-of-the art internal target at HESR FAIR detection identification neutral charged particles generated within relevant angular energy range. This report...
A detection system of the conventional PET tomograph is set-up to record data from e+ e- annihilation into two photons with energy 511 keV, and it gives information on density distribution a radiopharmaceutical in body object. In this paper we explore possibility performing three gamma imaging based ortho-positronium annihilation, as well positronium mean lifetime J-PET constructed plastic scintillators. For purposes simulations formation its were performed taking account distributions...
The Jagiellonian Positron Emission Tomograph (J-PET) is the first PET built from plastic scintillators.J-PET prototype consists of 192 detection modules arranged axially in three layers forming a cylindrical diagnostic chamber with inner diameter 85 cm and axial field-of-view 50 cm.An arrangement long strips scintillators, their small light attenuation, superior timing properties, relative ease increase opens promising perspectives for cost effective construction whole-body scanner, as well...
Positronium created in a human body during PET scans hallmarks neoplastic tissues.
We report on an exclusive and kinematically complete high-statistics measurement of the basic double-pionic fusion reaction pn→dπ(0)π(0) over full energy region ABC effect, a pronounced low-mass enhancement in ππ-invariant mass spectrum. The measurements, which cover also transition to conventional t-channel ΔΔ process, were performed with upgraded WASA detector setup at COSY. data reveal Abashian-Booth-Crowe effect be uniquely correlated Lorentzian dependence integral cross section....
Exclusive and kinematically complete high-statistics measurements of quasifree polarized $\stackrel{\ensuremath{\rightarrow}}{n}p$ scattering have been performed in the energy region narrow resonancelike structure ${d}^{*}$ with $I({J}^{P})=0({3}^{+})$, $M\ensuremath{\approx}2380\text{ }\text{ }\mathrm{MeV}$, $\mathrm{\ensuremath{\Gamma}}\ensuremath{\approx}70\text{ }\mathrm{MeV}$ observed recently double-pionic fusion channels...
The novel whole-body PET system based on plastic scintillators is developed by the {J-PET} Collaboration. It consists of scintillator strips arranged axially in form a cylinder, allowing cost-effective construction total-body PET. In order to determine properties scanner prototype and optimize its geometry, advanced computer simulations using GATE software were performed. spatial resolution, sensitivity, scatter fraction noise equivalent count rate estimated according NEMA norm as function...
The existence of a new force beyond the Standard Model is compelling because it could explain several striking astrophysical observations which fail standard interpretations. We searched for light vector mediator this dark force, $\mathrm{U}$ boson, with KLOE detector at DA$\Phi$NE $\mathrm{e}^{+}\mathrm{e}^{-}$ collider. Using an integrated luminosity 1.54 fb$^{-1}$, we studied process $\mathrm{e}^{+}\mathrm{e}^{-} \to \mathrm{U}\gamma$, $\mathrm{U} \mathrm{e}^{+}\mathrm{e}^{-}$, using...
We have searched for a light vector boson U, the possible carrier of "dark force", with KLOE detector at DAΦNE e+e− collider, motivated by astrophysical evidence presence dark matter in Universe. Using collisions collected an integrated luminosity 239.3 pb−1, we look dimuon mass peak reaction e+e−→μ+μ−γ, corresponding to decay U→μ+μ−. find no U signal. set 90% CL upper limit mixing parameter squared between photon and 1.6×10−5 8.6×10−7 region 520<mU<980 MeV.
The recent interest in a light gauge boson the framework of an extra U(1) symmetry motivates searches mass range below 1 GeV. We present search for such particle, dark photon, e+e−→Uγ, U→π+π− based on 28 million e+e−→π+π−γ events collected at DAΦNE by KLOE experiment. π+ π− production initial-state radiation compensates loss sensitivity previous U→e+e−, μ+μ− due to small branching ratios ρ–ω resonance region. found no evidence signal and set limit 90% CL mixing strength between photon ε2, U...
Charged lepton system symmetry under combined charge, parity, and time-reversal transformation (CPT) remains scarcely tested. Despite stringent quantum-electrodynamic limits, discrepancies in predictions for the electron-positron bound state (positronium atom) motivate further investigation, including fundamental tests. While CPT noninvariance effects could be manifested non-vanishing angular correlations between final-state photons spin of annihilating positronium, measurements were...
The purpose of the presented research is estimation performance characteristics economic Total-Body Jagiellonian-PET system (TB-J-PET) constructed from plastic scintillators. are estimated according to NEMA NU-2-2018 standards utilizing GATE package. simulated detector consists 24 modules, each built out 32 scintillator strips (each with cross section 6 mm times 30 and length 140 cm or 200 cm) arranged in two layers regular 24-sided polygon circumscribing a circle diameter 78.6 cm. For...
Positronium is abundantly produced within the molecular voids of a patient’s body during positron emission tomography (PET). Its properties dynamically respond to submolecular architecture tissue and partial pressure oxygen. Current PET systems record only two annihilation photons cannot provide information about positronium lifetime. This study presents in vivo images lifetime human, for patient with glioblastoma brain tumor, by using dedicated Jagiellonian system enabling simultaneous...
Discrete symmetries play an important role in particle physics with violation of CP connected to the matter-antimatter imbalance Universe. We report most precise test P, T and invariance decays ortho-positronium, performed methodology involving polarization photons from these decays. Positronium, simplest bound state electron positron, is recent interest discrepancies reported between measured hyperfine energy structure theory at level $10^{-4}$ signaling a need for better understanding...
This document describes the technical layout and expected performance of Straw Tube Tracker (STT), main tracking detector $\overline{P}$ ANDA target spectrometer. The STT encloses a Micro-Vertex-Detector (MVD) for inner is followed in beam direction by set GEM stations. tasks are measurement particle momentum from reconstructed trajectory specific energy loss identification. Dedicated simulations with full analysis studies certain proton-antiproton reactions, identified as being benchmark...
In this article it is presented an FPGA based $M$ulti-$V$oltage $T$hreshold (MVT) system which allows of sampling fast signals ($1-2$ ns rising and falling edge) in both voltage time domain. It possible to achieve a precision measurement $20$ ps RMS reconstruct charge signals, using simple approach, with deviation from real value smaller than 10$\%$. Utilization the differential inputs chip as comparators together implementation TDC inside allowed us compact multi-channel characterized by...
A novel approach to tomographic data processing has been developed and evaluated using the Jagiellonian PET (J-PET) scanner as an example. We propose a system in which there is no need for powerful, local facility, capable reconstruct images on fly. Instead we introduce Field Programmable Gate Array (FPGA) System-on-Chip (SoC) platform connected directly streams coming from scanner, can perform event building, filtering, coincidence search Region-Of-Response (ROR) reconstruction by...
Recent tests of a single module the Jagiellonian Positron Emission Tomography system (J-PET) consisting 30 cm long plastic scintillator strips have proven its applicability for detection annihilation quanta (0.511 MeV) with coincidence resolving time (CRT) 0.266 ns. The achieved resolution is almost by factor two better respect to current TOF-PET detectors and it can still be improved since, as shown in this article, intrinsic limit determination interaction 0.511 MeV gamma scintillators...