# Improved Bethe-Heitler formula

## TL;DR

This paper re-derives the bremsstrahlung cross section using time ordered perturbative theory, revealing screening effects missed by the traditional Bethe-Heitler formula, and highlights the importance of screening parameters.

## Contribution

It introduces a TOPT-based derivation of bremsstrahlung cross section that accounts for screening effects neglected in previous models.

## Key findings

- TOPT provides a new perspective on bremsstrahlung cross section
- Screening parameter significantly influences the cross section
- Traditional Bethe-Heitler formula misses screening effects

## Abstract

The bremsstrahlung cross section of electron in the atomic electric field is re-derived using the time ordered perturbative theory. The results are compared with the Bethe-Heitler formula. We indicate that both the TOPT-description and a soft version for the bremsstrahlung process predict a strong screening parameter-dependent cross section, which is missed by previous bremsstrahlung theory.

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Source: https://tomesphere.com/paper/1901.00102