Testing CPT symmetry in ortho-positronium decays with positronium annihilation tomography
Autor: | Muhsin Mohammed, Monika Pawlik-Niedźwiecka, Tomasz Kozik, S. S. Choudhary, Szymon Parzych, K. Kacprzak, R. Y. Shopa, Catalina Curceanu, Aleksander Gajos, Eryk Czerwiński, Lech Raczyński, J. Chhokar, Szymon Niedźwiecki, Wojciech Wiślicki, Marek Gorgol, Ewa Stępień, Michał Silarski, Wojciech Krzemien, Andrzej Sienkiewicz, Bożena Jasińska, Grzegorz Korcyl, Sushil K. Sharma, Paweł Moskal, F. Tayefi, N. Chug, Łukasz Kapłon, Konrad Klimaszewski, H. Karimi, Magdalena Skurzok, J. Raj, Ewelina Kubicz, Paweł Kowalski, N. Krawczyk, Kamil Dulski, Jacek Goworek, D. Kisielewska, M. Dadgar, Beatrix C. Hiesmayr |
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Jazyk: | angličtina |
Rok vydání: | 2021 |
Předmět: |
Particle physics
Photon CPT symmetry Science Physics::Medical Physics General Physics and Astronomy FOS: Physical sciences Imaging techniques General Biochemistry Genetics and Molecular Biology Article High Energy Physics - Experiment Positronium High Energy Physics - Experiment (hep-ex) Physics::Atomic and Molecular Clusters Experimental nuclear physics Nuclear Experiment (nucl-ex) Nuclear Experiment Spin-½ Physics Multidisciplinary Annihilation Operator (physics) High Energy Physics::Phenomenology General Chemistry Symmetry (physics) High Energy Physics::Experiment Experimental particle physics Lepton |
Zdroj: | Nature Communications, Vol 12, Iss 1, Pp 1-9 (2021) Nature Communications |
Popis: | 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 symmetry tests. While CPT noninvariance effects could be manifested in non-vanishing angular correlations between final-state photons and spin of annihilating positronium, measurements were previously limited by knowledge of the latter. Here, we demonstrate tomographic reconstruction techniques applied to three-photon annihilations of ortho-positronium atoms to estimate their spin polarisation without magnetic field or polarised positronium source. We use a plastic-scintillator-based positron-emission-tomography scanner to record ortho-positronium (o-Ps) annihilations with single-event estimation of o-Ps spin and determine the complete spectrum of an angular correlation operator sensitive to CPT-violating effects. We find no violation at the precision level of 10^{-4}, with an over threefold improvement on the previous measurement. Comment: This is a preprint of an article published in Nature Communications. The final version is available at https://rdcu.be/cCQqq |
Databáze: | OpenAIRE |
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