Gamma-Z box corrections to weak charges of heavy nuclei in atomic parity   violation
  We present a new dispersive formulation of the gamma-Z box radiative corrections to weak charges of bound protons and neutrons in atomic parity violation (APV) measurements on heavy nuclei such as 133-Cs and 213-Ra. We evaluate for the first time a small but important additional correction arising from Pauli blocking of nucleons in a heavy nucleus. Overall, we find a significant shift in the gamma-Z correction to the weak charge of 133-Cs, approximately 4 times larger than the current uncertainty on the value of sin^2(theta_W), but with a reduced error compared to earlier estimates. 
P. G. Blunden, W. Melnitchouk, and A. W. Thomas
hep-ph nucl-th