QED radiative corrections to parity nonconservation in heavy atoms

The self-energy and vertex QED radiative corrections [similar toZalpha(2)f(Zalpha)] are shown to give a large negative contribution to the parity nonconserving (PNC) amplitude in heavy atoms. The correction -0.73(20)% found for the 6s-7s PNC amplitude in Cs-133 brings the experimental result for this transition into agreement with the standard model. The calculations are based on a new relation that expresses the radiative corrections to the PNC matrix element via corrections to the energy shifts induced by the finite nuclear size.