학술논문
Discrete symmetries tested at 10$^{-4}$ precision using linear polarization of photons from positronium annihilations
Document Type
Working Paper
Author
Moskal, Paweł; Czerwiński, Eryk; Raj, Juhi; Bass, Steven D.; Beyene, Ermias Y.; Chug, Neha; Coussat, Aurélien; Curceanu, Catalina; Dadgar, Meysam; Das, Manish; Dulski, Kamil; Gajos, Aleksander; Gorgol, Marek; Hiesmayr, Beatrix C.; Jasińska, Bożena; Kacprzak, Krzysztof; Kaplanoglu, Tevfik; Kapłon, Łukasz; Klimaszewski, Konrad; Konieczka, Paweł; Korcyl, Grzegorz; Kozik, Tomasz; Krzemień, Wojciech; Kumar, Deepak; Moyo, Simbarashe; Mryka, Wiktor; Niedźwiecki, Szymon; Parzych, Szymon; del Río, Elena Pérez; Raczyński, Lech; Sharma, Sushil; Choudhary, Shivani; Shopa, Roman Y.; Silarski, Michał; Skurzok, Magdalena; Stępień, Ewa Ł.; Tanty, Pooja; Ardebili, Faranak Tayefi; Ardebili, Keyvan Tayefi; Eliyan, Kavya Valsan; Wiślicki, Wojciech
Source
Nature Communications 15, 78 (2024)
Subject
Language
Abstract
Discrete symmetries play an important role in particle physics with violation of CP connected to the matter-antimatter imbalance in the Universe. We report the most precise test of P, T and CP invariance in decays of ortho-positronium, performed with methodology involving polarization of photons from these decays. Positronium, the simplest bound state of an electron and positron, is of recent interest with discrepancies reported between measured hyperfine energy structure and theory at the level of $10^{-4}$ signaling a need for better understanding of the positronium system at this level. We test discrete symmetries using photon polarizations determined via Compton scattering in the dedicated J-PET tomograph on an event-by-event basis and without the need to control the spin of the positronium with an external magnetic field, in contrast to previous experiments. Our result is consistent with QED expectations at the level of 0.0007 and one standard deviation.
Comment: 17 pages, 10 figures
Comment: 17 pages, 10 figures