Vacuum polarization radiative correction to the parity violating   electron scattering on heavy nuclei
  The effect of vacuum polarization on the parity violating asymmetry in the elastic electron-nucleus scattering is considered. Calculations are performed in the high-energy approximation with an exact account for the electric field of the nucleus. It is shown that the radiative correction to the parity violating asymmetry is logarithmically enhanced and the value of the correction is about -1%. 
A. I. Milstein, O. P. Sushkov