The worldline approach to helicity flip in plane waves

TL;DR

This paper employs worldline methods to analyze vacuum polarization and helicity-flip probabilities in plane wave backgrounds within scalar and spinor QED, offering a new toolkit for higher-order process investigations.

Contribution

It introduces a novel application of worldline techniques to compute helicity-flip probabilities exactly in plane wave backgrounds, connecting different theoretical approaches.

Findings

Calculated helicity-flip probabilities at one loop order.

Developed a toolkit for higher-order process analysis.

Established connections between worldline, S-matrix, and lightfront methods.

Abstract

We apply worldline methods to the study of vacuum polarisation effects in plane wave backgrounds, in both scalar and spinor QED. We calculate helicity-flip probabilities to one loop order and treated exactly in the background field, and provide a toolkit of methods for use in investigations of higher-order processes. We also discuss the connections between the worldline, S-matrix, and lightfront approaches to vacuum polarisation effects.