Using nonlinear Breit-Wheeler to test nonlinear vacuum birefringence

TL;DR

This paper proposes using the nonlinear Breit-Wheeler process in upcoming laser experiments to measure and confirm the quantum vacuum's birefringence, a phenomenon predicted by quantum electrodynamics but not yet experimentally verified.

Contribution

It introduces a novel method to measure nonlinear vacuum birefringence through photon-polarized nonlinear Breit-Wheeler processes in future laser experiments.

Findings

Calculated measurement accuracy for upcoming experiments

Demonstrated feasibility of using nonlinear Breit-Wheeler for birefringence detection

Linked photon-polarized processes to vacuum birefringence measurement

Abstract

Quantum electrodynamics predicts that the quantum vacuum is birefringent, but due to the very small cross-section this is yet to be confirmed by experiment. Vacuum birefringence arises as the elastic part of photon-photon scattering; the inelastic part is Breit-Wheeler pair-production. We outline how measurements of the photon-polarised nonlinear Breit-Wheeler process can be used to infer a measurement of nonlinear vacuum birefringence. As an example scenario, we calculate the accuracy of such a measurement for parameters anticipated at upcoming laser-particle experiments.