Coulomb correction to the spectral bremsstrahlung rate in the quantum Migdal theory of the Landau-Pomeranchuk effect

TL;DR

This paper analytically and numerically evaluates Coulomb corrections to the spectral bremsstrahlung rate within the quantum Migdal theory of the LPM effect, highlighting significant corrections up to -19% relevant for high-energy electromagnetic cascade simulations.

Contribution

It provides refined analytical and numerical Coulomb correction calculations for the quantum Migdal theory across various Z and B regimes, improving accuracy in high-energy physics models.

Findings

Coulomb corrections can reach -19% in spectral bremsstrahlung rates.

Corrections are significant for Monte Carlo simulations of high-energy electromagnetic showers.

The study extends the understanding of Coulomb effects in the LPM regime.

Abstract

High-energy Coulomb corrections (CCs) to some quantities of the quantum Migdal theory of the Landau-Pomeranchuk-Migdal (LPM) effect are obtained analytically and numerically for the regimes of small and strong LPM suppression on the basis of a refined Moliere multiple scattering theory. Numerical calculations are presented in the ranges of the nuclear charge number Z of a scatterer from 6 to 92 and the expansion parameter B of Moliere from 4.5 to 8.5. It is shown that the relative CC to the spectral bremsstrahlung rate can reach a value of the order of -19% in the ranges considered and must be borne in mind, e.g., in the Monte-Carlo analysis of electromagnetic cascade LPM showers in extremely high-energy region.