# Time Reversal Invariance at COSY (TRIC)

The TRIC project was initiated as one of the first attempts to test a fundamental symmetry at COSY. The project aims to improve the present upper limit on T-symmetry violation in the hadronic sector by at least one order of magnitude. The violation of T-symmetry is needed to explain one of the fundamental problems of the Standard Model - the Baryon Asymmetry of the Universe: where is the antimatter?

The experiment aims to measure a unique genuine null observable available in double polarized proton-deuteron scattering to the level of 10-6. The TRIC experiment is constructed as a transmission experiment in the storage ring which makes use of the optical theorem for the total cross section determination in double polarized scattering. This implies that the cross section will not be determined by measuring all the particles scattered from the beam-target interaction but rather from the beam current decrease with time due to interaction of the polarized proton beam with the tensor polarized deuterium target. Hence, the experiment crucially depends on the relative resolution of the beam current measurement which is used as a tool for the T-symmetry violation search.

The PAX@COSY installation is ideally suited for TRIC, hence since 2010 the TRIC experiment is part of the experimental program of the PAX collaboration.

# Local contact persons in IKP-2:



Dr. Yury Valdau

Prof. Hans Ströher



# Summarizing papers:



Beam current measurement

Possible systematic errors

Feasibility test at PAX

Basic ideas





PAX Collaboration

TRIC Wiki (Internal)