Discrete symmetries tested at 10−4 precision using linear polarization of photons from positronium annihilations

Paweł Moskal, Eryk Czerwiński (Corresponding author), Juhi Raj, Steven D. Bass, Ermias Y. Beyene, Neha Chug, Aurélien Coussat, Catalina Curceanu, Meysam Dadgar, Manish Das, Kamil Dulski, Aleksander Gajos, Marek Gorgol, Beatrix C. Hiesmayr, Bożena Jasińska, Krzysztof Kacprzak, Tevfik Kaplanoglu, Łukasz Kapłon, Konrad Klimaszewski, Paweł KonieczkaGrzegorz Korcyl, Tomasz Kozik, Wojciech Krzemień, Deepak Kumar, Simbarashe Moyo, Wiktor Mryka, Szymon Niedźwiecki, Szymon Parzych, Elena Pérez del Río, Lech Raczyński, Sushil Sharma, Shivani Choudhary, Roman Y. Shopa, Michał Silarski, Magdalena Skurzok, Ewa Stępień, Pooja Tanty, Faranak Tayefi Ardebili, Keyvan Tayefi Ardebili, Kavya Valsan Eliyan, Wojciech Wiślicki

Publications: Contribution to journalArticlePeer Reviewed

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.

Original languageEnglish
Article number78
Number of pages10
JournalNature Communications
Volume15
Issue number1
DOIs
Publication statusPublished - Jan 2024

Austrian Fields of Science 2012

  • 103034 Particle physics
  • 103012 High energy physics

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