Charge asymmetry in electron/positron energy loss in nuclear Bremsstrahlung

TL;DR

This paper calculates the Coulomb correction to electron and positron energy loss in nuclear Bremsstrahlung, revealing charge asymmetry effects across different energy regimes using advanced multiloop techniques.

Contribution

It introduces a novel calculation of Coulomb corrections to energy loss, explicitly quantifying charge asymmetry in electron/positron Bremsstrahlung for arbitrary energies.

Findings

Charge asymmetry depends on energy and is characterized by polylogarithms.

Provides asymptotic formulas for both threshold and high-energy regimes.

Results align with and extend previous findings in the field.

Abstract

We calculate the leading Coulomb correction to the energy loss in the electron-nucleus Bremsstrahlung for arbitrary energy of the incoming particle. This correction determines the charge asymmetry, i.e., the difference of electron and positron energy loss. The result is presented in terms of the classical polylogarithms $\mathrm{Li}_2$ and $\mathrm{Li}_3$. We use modern multiloop methods based on the IBP reduction and on the differential equations for master integrals. We provide both the threshold and the high-energy asymptotics of the found asymmetry and compare them with the available results.