Constraints on the dark photon from parity violation and the W mass

Abstract

We present an analysis of the experimental data for parity violating electron scattering and atomic parity violation, including the effects of a dark photon. We derive the favored region of dark photon parameter space, which provides a good description of the experimental data from the Qweak Collaboration and the Jefferson Lab PVDIS Collaboration and simultaneously relieves the tension between the neutron skin thickness determined in the PREX-II experiment and nuclear-model predictions. In addition, we extract the parameter region required to explain the latest W-boson mass anomaly. Our results indicate that a heavy dark photon with mass above the Z-boson mass is favored, while other sources of new physics beyond the Standard Model in addition to the dark photon would also be expected.