Reconciliation of the measurement of parity nonconservation in Cs with the standard model

Abstract

Contributions from the Breit interaction in atomic structure calculations account for 1.3sigma of the previously reported 2. 5sigma deviation from the standard model in the 133Cs weak charge [S. C. Bennett and C. E. Wieman, Phys. Rev. Lett. 82, 2484 (1999)]. The updated corrections for the neutron distribution reduce the discrepancy further to 1.0sigma. The updated value of the weak charge is Q(W)(133Cs) = -72.65(28)(expt)(34)(theor).