Parity nonconservation in heavy atoms: the radiative correction enhanced by the strong electric field of the nucleus

Full text: Parity nonconservation due to the nuclear weak charge is considered. We demonstrate that the radiative corrections to this effect due to the vacuum fluctuations of the characteristic size larger than the nuclear radius r0 and smaller than the electron Compton wave-length λ0 are enhanced because of the strong electric field of the nucleus. The parameter that allows one to classify the corrections is the large logarithm ln(λc/r0). The vacuum polarization contribution is enhanced by the second power of the logarithm. Although the self-energy and the vertex corrections do not vanish, they contain only the first power of the logarithm. The value of the radiative is 0.4% for Cs and 0.9% for Tl, Pb, and Bi. We discuss also how the correction affects the interpretation of the experimental data on parity nonconservation in atoms