New physics constraints from atomic parity violation in Cs 133

Abstract

Our improved calculation of the nuclear spin-independent parity violating electric dipole transition amplitude (E1PV) for 6sS21/2-7sS21/2 in Cs133 in combination with the most accurate (0.3%) measurement of this quantity yields a new value for the nuclear weak charge QW=-73.71(26)ex(23)th against the Standard Model (SM) prediction QWSM=-73.23(1). The advances in our calculation of E1PV have been achieved by using a variant of the perturbed relativistic coupled-cluster theory, which treats the contributions of the core, valence, and excited states to E1PV on the same footing unlike the previous high precision calculations. Furthermore, this approach resolves the controversy regarding the sign of the core correlation effects. We discuss the implications of the deviation of our result for QW from the SM value by considering different scenarios of new physics.