Studies of discrete symmetries in decays of positronium atoms

E Czerwiński ,Beatrix C Hiesmayr,Marcin Zieliński,Szymon Niedźwiecki,M Skurzok ,W Migdał ,P Kowalski ,M Pałka ,T Kozik ,Z Rudy ,M Silarski ,E Kubicz ,A Heczko ,M Pawlik-Niedźwiecka ,M Mohammed ,G Korcyl ,J Raj ,A Gajos ,K Dulski ,B Jasińska ,C Curceanu ,Sushil Sharma ,W Wiślicki ,L Raczyński ,Shivani Shivani ,D Kisielewska ,B Zgardzińska ,R Y Shopa ,Bartłomiej Korzeniak ,W Krzemień ,M Gorgol ,P Moskal

doi:10.1051/epjconf/201818101019

Abstract

A positronium - a bound state of electron and positron - is an eigenstate of parity and charge conjugation operators which decays into photons. It is a unique laboratory to study discrete symmetries whose precision is limited, in principle, by the effects due to the weak interactions expected at the level of 10−14 and photon-photon interactions expected at the level of 10−9. The Jagiellonian Positron Emission Tomograph (J-PET) is a detector for medical imaging as well as for physics studies involving detection of electronpositron annihilation into photons. The physics case covers the areas of discrete symmetries studies and genuine multipartite entanglement. The J-PET detector has high angular and time resolution and allows for determination of spin of the positronium and the momenta and polarization vectors of annihilation quanta. In this article, we present the potential of the J-PET system for studies of discrete symmetries in decays of positronium atoms.

Highlights

Various systems, like the accelerator neutrinos [1], mesons [2] or nuclei [3], can be used as probes for investigations of charge conjugation (C), parity (P) and time reversal (T) discrete symmetries
It is a unique laboratory to study discrete symmetries whose precision is limited, in principle, by the effects due to the weak interactions expected at the level of 10−14 and photon-photon interactions expected at the level of 10−9
We present the potential of the Jagiellonian Positron Emission Tomograph (J-PET) system for studies of discrete symmetries in decays of positronium atoms

Summary

Introduction

Like the accelerator neutrinos [1], mesons [2] or nuclei [3], can be used as probes for investigations of charge conjugation (C), parity (P) and time reversal (T) discrete symmetries. The search for CP and CPT violation was performed in the decays of a bound state of electron and positron (positronium) [4, 5]. This bound state is considered for observation of the gravitational quantum states [6]. Measurement of the expectation values of symmetryodd operators for the o-Ps → 3γ process will test the other fundamental symmetries and their combinations. Such operators can be constructed from o-Ps spin (S ) and momentum of annihilation quantum (ki). The operators with annihilation quantum polarization ( i) are uniquely available at the J-PET system [13]

The J-PET detector

The experimental technique