Feasibility study of the time reversal symmetry tests in decays of metastable positronium atoms with the J-PET detector

TL;DR

This study explores the potential of the J-PET detector to test time reversal symmetry in positronium decays, proposing strategies and analyzing pilot data to assess sensitivity to T violation in leptonic systems.

Contribution

It introduces two novel strategies for detecting T violation in positronium decays and evaluates the J-PET detector's performance in this context.

Findings

Pilot measurement demonstrates J-PET's capability in reconstructing three-photon decays.

Assessment indicates potential sensitivity to T-violation observables.

Proposed strategies could enable new tests of fundamental symmetries in leptonic systems.

Abstract

This article reports on the feasibility of testing of the symmetry under reversal in time in a purely leptonic system constituted by positronium atoms using the J-PET detector. The present state of T symmetry tests is discussed with an emphasis on the scarcely explored sector of leptonic systems. Two possible strategies of searching for manifestations of T violation in non-vanishing angular correlations of final state observables in the decays of metastable triplet states of positronium available with J-PET are proposed and discussed. Results of a pilot measurement with J-PET and assessment of its performance in reconstruction of three-photon decays are shown along with an analysis of its impact on the sensitivity of the detector for the determination of T -violation sensitive observables.