QED corrections to elastic electron-nucleus scattering beyond the first-order Born approximation

TL;DR

This paper develops a nonperturbative approach to include QED corrections in elastic electron-nucleus scattering, revealing significant deviations from first-order Born results, especially at higher momentum transfers.

Contribution

It introduces a method to incorporate vertex, self-energy, and vacuum polarization corrections into the Dirac equation for more accurate scattering calculations.

Findings

Significant deviation from Born approximation at higher momentum transfer.

QED corrections increase with target atomic number and momentum transfer.

Estimates for corrections to beam-normal spin asymmetry are provided.

Abstract

A potential for the vertex and self-energy correction is derived from the first-order Born theory. The inclusion of this potential in the Dirac equation, together with the Uehling potential for vacuum polarization, allows for a nonperturbative treatment of these QED effects within the phase-shift analysis. Investigating the 12C and 208Pb targets, a considerable deviation of the respective cross-section change from the Born results is found, which becomes larger with increasing momentum transfer. Estimates for the correction to the beam-normal spin asymmetry are also provided. For the 12C nucleus, dispersion effects are considered as well.