Breit interaction and parity nonconservation in many-electron atoms

We present accurate ab initio nonperturbative calculations of the Breit correction to the parity nonconserving (PNC) amplitudes of the 6s-7s and 6s-5d_3∕2 transitions in Cs, 7s-8s and 7s-6d_3∕2 transitions in Fr, 6s-5d_3∕2 transition in Ba⁺, 7s-6d_3∕2 transition in Ra⁺, and 6p_1∕2-6p_3∕2 transition in Tl. The results for the 6s-7s transition in Cs and 7s-8s transition in Fr are in good agreement with other calculations. We demonstrate that higher-orders many-body corrections to the Breit interaction are especially important for the s-d PNC amplitudes. We confirm good agreement of the PNC measurements for cesium and thallium with the standard model.