High accuracy calculation of 6s -> 7s parity nonconserving amplitude in Cs

Abstract

We calculated the parity nonconserving (PNC) 6s -> 7s amplitude in Cs. In the Dirac-Coulomb approximation our result is in a good agreement with other calculations. Breit corrections to the PNC amplitude and to the Stark-induced amplitude $\beta$ are found to be -0.4% and -1% respectively. The weak charge of ${}^{133}$Cs is $Q_W=-72.5\pm 0.7$ in agreement with the standard model.

Comments: 4 pages, LaTeX2e, uses revtex4.cls, submitted to PRL