Parity and time reversal experiments in atoms

Abstract

There has been exciting progress in recent years in measuring parity nonconservation in atoms as a probe of the fundamental electroweak force, and in searching for a permanent electric dipole moment of atoms and molecules as a test of time reversal symmetry. We are carrying out experiments of each type: a measurement of parity nonconserving optical rotation in atomic lead vapor, and a search for an electric dipole on mercury atoms. We describe both experiments and report our most recent results, including the smallest upper limit to date on an electric dipole moment, ‖ d(199Hg) ‖<2×10−27 ecm, which sets new constraints on possible T‐violating interactions among elementary particles.