The existence of new mechanisms of CP violation is one of the necessary conditions to explain the matter-antimatter asymmetry in the Universe. Searches for new mechanisms of CP (or T)-violation are being carried out in precision measurements of electric dipole moments of particles, nuclei, atoms, and molecules as well as in properly selected correlations in decay processes. Positronium (Ps) is a purely leptonic state that decays into photons. The observation of a CP violating correlation associated with the decay process, at the current level of sensitivity, would provide a signature of physics beyond the Standard Model. A CP violating correlation can be formed in Ps decay, involving the tensor polarization and the momenta of the two highest energy photons in the three-photon decay of ortho-Ps. We have designed and built a new apparatus to search for CP-violation in ortho-Ps decay with an order of magnitude improved sensitivity relative to previous work. This talk will present the driving elements for its design and optimization, which includes a photon detector array and the Ps formation medium and will discuss the improved sensitivity of the design.

IFIC seminar organizers