The neutron EDM and bounds on rare decays of eta and eta-prime mesons

Abstract

We complete our derivation of upper limits on the CP violating ηππ and η‘ππ couplings from an analysis of their two-loop contribution to the neutron electric dipole moment (nEDM). As a result we obtain numerical upper limits for the ηππ and η‘ππ branchings and couplings which are important for planned experiments at JLab. We also derive upper limits on the CP violating θ̅parameter of QCD θ̅< 2.8 × 10−10