QED Radiative Corrections to Parity Nonconservation in Heavy Atoms

The self-energy and vertex QED radiative corrections [$\sim Z{\alpha }^{2}f\left(Z\alpha \right)$] are shown to give a large negative contribution to the parity nonconserving (PNC) amplitude in heavy atoms. The correction $-0.73\left(20\right)\%$ found for the $6s\mathrm{\text{−}}7s$ PNC amplitude in ${}^{\mathrm{133}}\mathrm{C}\mathrm{s}$ 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.