Speaker
Description
Electric dipole moments (EDMs) of nucleons, nuclei, and atoms provide highly sensitive probes of new sources of CP violation beyond the Standard Model. A central challenge is the “EDM inverse problem”: determining the underlying ultraviolet origin of CP violation from a pattern of low-energy EDM measurements. In this talk, I discuss how solutions to the strong CP problem, particularly the QCD axion, modify the expected correlations among EDM observables. We show that combined measurements of light systems, including the neutron, proton, deuteron, and helium nuclei, can identify the dominant hadronic CP-odd operator, whereas heavy-atom EDMs generally provide only suggestive discrimination. In particular, a pattern consistent with quark chromo-electric dipole moments as the dominant source of nucleon EDMs could offer indirect experimental evidence for the QCD axion.