High-precision calculation of parity nonconservation in cesium and test of the standard model

We calculate the 6s-7s parity nonconserving (PNC) $E1$ transition amplitude EPNC in cesium. We use an improved all-order technique in the calculation of the correlations and include all significant contributions to EPNC. Our final value EPNC=0.904(1±0.5%)×10^-11ieaB(-QW/N) has half the uncertainty claimed in old calculations used for the interpretation of Cs PNC experiments. The resulting nuclear weak charge QW for Cs deviates by about 2σ from the value predicted by the standard model.