CP-violating Moments of Atoms and Nuclei

Permanent electric dipole moments (EDMs) of physical systems indicate both parity (P) and time-reversal (T) violations, and thus charge-conjugation-parity (CP) violation through CPT invariance. As the Standard Model prediction for these EDMs are negligible background, EDM measurements provide powerful probes of CP violation and help to constrain new physics, which often anticipates much larger flavor-diagonal CP violation.

The EDM experiments cover a wide range of systems from leptons, nucleons, nuclei, atoms, molecules, to solid states. In this talk, I will briefly overview these searches with focus on nuclei and atoms, and discuss the important screening effect, which affects EDM measurements in neutral systems. Finally I will outline the new-generation experiments along with our theoretical effort (*) which aims at sharpening the interpretation of EDM measurements at atomic and nuclear physics levels.