Mapping the Electromagnetic Fields of Heavy-Ion Collisions with the Breit-Wheeler Process

TL;DR

This paper reviews recent theoretical and experimental progress in mapping ultra-strong electromagnetic fields generated in heavy-ion collisions through the Breit-Wheeler process, providing insights into the fields' strength and spatial distribution.

Contribution

It introduces new methods for using the Breit-Wheeler process as a purely electromagnetic probe in heavy-ion collision experiments.

Findings

Demonstration of photon interactions in collisions with hadronic overlap

Measurement of dilepton distributions reveals electromagnetic field characteristics

Advances in experimental techniques for detecting Breit-Wheeler pairs

Abstract

Ultra-relativistic heavy-ion collisions are expected to produce the strongest electromagnetic fields in the known Universe. These highly-Lorentz contracted fields can manifest themselves as linearly polarized quasi-real photons that can interact via the Breit-Wheeler process to produce lepton anti-lepton pairs. The energy and momentum distribution of the produced dileptons carry information about the strength and spatial distribution of the colliding fields. Recently it has been demonstrated that photons from these fields can interact even in heavy-ion collisions with hadronic overlap, providing a purely electromagnetic probe of the produced medium. In this review we discuss the recent theoretical progress and experimental advances for mapping the ultra-strong electromagnetic fields produced in heavy-ion collisions via measurement of the Breit-Wheeler process.