Radiative corrections to the parity-violating spin asymmetry

Abstract

The parity-violating spin asymmetry Apv for elastic electron scattering from spin-zero nuclei, together with its QED corrections, is evaluated non-perturbatively within the phase-shift analysis. Dispersion corrections, taking into account low-lying transient nuclear excitations, are estimated with the help of the lowest-order $\gamma Z$ box diagrams. Collision energies between 5 $-$ 500 MeV are considered, and results are provided for the ${}^{12}$C and ${}^{208}$Pb target nuclei. In addition, we have evaluated Apv at GeV energies and small scattering angles -- relevant for the Pb Radius Experiment (PREx) -- revealing that the low-lying nuclear excited states give no measurable dispersive contribution. However, they are important at lower energies and backward angles.

Comments: Accepted version (PRC)