Treating Coulomb exchange contributions in relativistic mean field calculations: why and how

TL;DR

This paper demonstrates that Coulomb exchange effects in relativistic mean field calculations can be accurately included using a perturbative approach, improving the predictive power of nuclear energy density functionals.

Contribution

It introduces a simple perturbative method to incorporate Coulomb exchange contributions in relativistic EDF models, enhancing their accuracy.

Findings

Coulomb exchange effects can be accurately approximated perturbatively.

Including Coulomb exchange improves the predictive accuracy of nuclear models.

The method is computationally efficient and easy to implement.

Abstract

The energy density functional (EDF) method is very widely used in nuclear physics, and among the various existing functionals those based on the relativistic Hartree (RH) approximation are very popular because the exchange contributions (Fock terms) are numerically rather onerous to calculate. Although it is possible to somehow 'mock up' the effects of meson-induced exchange terms by adjusting the meson-nucleon couplings, the lack of Coulomb exchange contributions hampers the accuracy of predictions. In this note, we show that the Coulomb exchange effects can be easily included with a good accuracy in a perturbative approach. Therefore, it would be desirable for future relativistic EDF models to incorporate Coulomb exchange effects, at least to some order of perturbation.