GammaZ box corrections to weak charges of heavy nuclei in atomic parity violation

We present a new dispersive formulation of the γZ box radiative corrections to weak charges of bound protons and neutrons in atomic parity violation measurements on heavy nuclei such as ¹³³Cs and ²¹³Ra. 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 γZ correction to the weak charge of ¹³³Cs, approximately 4 times larger than the current uncertainty on the value of sin²θ[sub]W, but with a reduced error compared to earlier estimates.P. G. Blunden, W. Melnitchouk, and A. W. Thoma