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In oncology, Positron Emission Tomography imaging is widely used in diagnostics of cancer metastases, in monitoring of progress in course of the cancer treatment, and in planning radiotherapeutic interventions. Accurate and reproducible…

Computer Vision and Pattern Recognition · Computer Science 2016-11-01 Jakub Czakon , Filip Drapejkowski , Grzegorz Zurek , Piotr Giedziun , Jacek Zebrowski , Witold Dyrka

Background: Beta-decay spectroscopy provides valuable nuclear physics input for thermonuclear reaction rates of astrophysical interest and stringent test for shell-model theories far from the stability line. Purpose: The available decay…

We present a precise theoretical prediction for the decay width of the bound state of two electrons and a positron (a negative positronium ion), Gamma(Ps^-) = 2.087 085(12)/ns. We include O(alpha^2) effects of hard virtual photons as well…

High Energy Physics - Phenomenology · Physics 2008-11-26 Mariusz Puchalski , Andrzej Czarnecki , Savely G. Karshenboim

The electron-positron annihilation spectrum observed by SPI/INTEGRAL during deep Galactic Center region exposure is reported. The line energy (510.954$\pm$0.075 keV) is consistent with the unshifted annihilation line. The width of the…

Astrophysics · Physics 2009-11-10 E. Churazov , R. Sunyaev , S. Sazonov , M. Revnivtsev , D. Varshalovich

The Jagiellonian positron emission tomograph (J-PET) is a multi-purpose device built out of plastic scintillators. With large acceptance and high angular resolution, it is suitable for the studies of various phenomena such as discrete…

Instrumentation and Detectors · Physics 2020-02-19 J. Chhokar

We present a calculation of the branching ratio of orthopositronium decay into an invisible mode, which is done in the context of Mirror World models, where ordinary positronium can disappear from our world due to oscillation into its…

High Energy Physics - Phenomenology · Physics 2013-05-30 S. V. Demidov , D. S. Gorbunov , A. A. Tokareva

The authors of Ref.[1] (referred to here as "Moskal et al.") claim to have performed the most precise test of P, T and CP invariance in the decay of ortho-Positronium. In this note: 1) we demonstrate, assuming standard properties for…

High Energy Physics - Phenomenology · Physics 2024-06-25 E. A. George , T. E. Haugen , O. Naviliat-Cuncic , P. A. Voytas

Monte Carlo Simulation (MCS) is a state-of-the-art technique in designing sophisticated apparatus for various applications in science and technology. We adopted MCS based on GEANT (GEometry ANd Tracking) in order to design a simple…

Medical Physics · Physics 2010-06-30 Nagendra Nath Mondal

Low-dose Positron Emission Tomography (PET) reduces radiation exposure but suffers from severe noise and quantitative degradation. Diffusion-based denoising models achieve strong final reconstructions, yet their reverse trajectories are…

Neurological Positron Emission Tomography (PET) is a critical imaging modality for diagnosing and studying neurodegenerative diseases like Alzheimer's disease. However, the inherent low spatial resolution of PET images poses significant…

Medical Physics · Physics 2025-02-24 Matthew Tivnan , Quanzheng Li

A long-standing problem to account for the electron-positron annihilation in positron Hydrogen scattering above the Positronium formation threshold has been resolved by the use of the three-body Faddeev formalism. The multichannel…

Atomic Physics · Physics 2007-05-23 S. L. Yakovlev , C-. Y. Hu

Positron emission tomography (PET) is a widely used, highly sensitive molecular imaging in clinical diagnosis. There is interest in reducing the radiation exposure from PET but also maintaining adequate image quality. Recent methods using…

Image and Video Processing · Electrical Eng. & Systems 2024-10-28 Yuxin Xue , Lei Bi , Yige Peng , Michael Fulham , David Dagan Feng , Jinman Kim

Single Photon Emission Computed Tomography (SPECT) is a non-invasive imaging modality, frequently used in myocardial perfusion imaging. The biggest challenges facing the majority of clinical SPECT systems are low sensitivity, poor…

Medical Physics · Physics 2021-03-30 Narayan Bhusal

We present new developments, based on beam tests and cosmic rays, on the gaseous photomultiplier (GasPM). The GasPM detects photons by combining a photocathode with a resistive-plate-chamber avalanche. It achieves $\mathcal{O}$(10) ps time…

Instrumentation and Detectors · Physics 2026-05-25 Simone Garnero , Kenji Inami , Kodai Matsuoka , Ryogo Okubo , Koichi Ueda

The positronium, as the lightest purely leptonic bound state, provides an ideal testing ground for a quantum field--theoretical (QFT) description of composite systems. While its electromagnetic annihilation is well understood as the…

High Energy Physics - Phenomenology · Physics 2025-11-18 Milena Piotrowska , Francesco Giacosa

The Positron Puzzle is a half-century old conundrum about the origin of the Galactic $\gamma$-ray emission line at photon energies of 511 keV, and the shape of its morphology, showing a bulge-to-disk luminosity ratio of $\sim 1$ - unlike…

High Energy Astrophysical Phenomena · Physics 2023-04-19 Thomas Siegert

Recent studies of positron emission tomography (PET) devices have shown that the detection of polarization-correlated annihilation quanta can potentially reduce the background and creation of false lines of response (LORs) leading to…

Positron Emission Tomography (PET) is a powerful molecular imaging tool that plays a crucial role in modern medical diagnostics by visualizing radio-tracer distribution to reveal physiological processes. Accurate organ segmentation from PET…

Computer Vision and Pattern Recognition · Computer Science 2026-03-13 Yichi Zhang , Le Xue , Wenbo Zhang , Lanlan Li , Yuchen Liu , Chen Jiang , Yuan Cheng , Yuan Qi
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