Discrete symmetries tested at 10$^{-4}$ precision using linear polarization of photons from positronium annihilations
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 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.
Keywords
Cite
@article{arxiv.2401.12092,
title = {Discrete symmetries tested at 10$^{-4}$ precision using linear polarization of photons from positronium annihilations},
author = {Paweł Moskal and Eryk Czerwiński and Juhi Raj and Steven D. Bass and Ermias Y. Beyene and Neha Chug and Aurélien Coussat and Catalina Curceanu and Meysam Dadgar and Manish Das and Kamil Dulski and Aleksander Gajos and Marek Gorgol and Beatrix C. Hiesmayr and Bożena Jasińska and Krzysztof Kacprzak and Tevfik Kaplanoglu and Łukasz Kapłon and Konrad Klimaszewski and Paweł Konieczka and Grzegorz Korcyl and Tomasz Kozik and Wojciech Krzemień and Deepak Kumar and Simbarashe Moyo and Wiktor Mryka and Szymon Niedźwiecki and Szymon Parzych and Elena Pérez del Río and Lech Raczyński and Sushil Sharma and Shivani Choudhary and Roman Y. Shopa and Michał Silarski and Magdalena Skurzok and Ewa Ł. Stępień and Pooja Tanty and Faranak Tayefi Ardebili and Keyvan Tayefi Ardebili and Kavya Valsan Eliyan and Wojciech Wiślicki},
journal= {arXiv preprint arXiv:2401.12092},
year = {2024}
}
Comments
17 pages, 10 figures