Hot Topics in Ultra-Peripheral Collisions

TL;DR

This paper introduces ultra-peripheral collisions of heavy ions, emphasizing their electromagnetic interactions, large cross sections, and key physics topics, based on a workshop discussion from 2001.

Contribution

It provides an overview of ultra-peripheral collisions and highlights four significant physics topics, offering insights into electromagnetic interactions in heavy-ion collisions.

Findings

Large cross sections due to coherent electromagnetic interactions

Identification of four key physics topics in ultra-peripheral collisions

Introduction to electromagnetic probes in fundamental physics

Abstract

Ultra-peripheral collisions of relativistic heavy ions involve long-ranged electromagnetic interactions at impact parameters too large for hadronic interactions to occur. The nuclear charges are large; with the coherent enhancement, the cross sections are also large. Many types of photonuclear and purely electromagnetic interactions are possible. We present here an introduction to ultra-peripheral collisions, and present four of the most compelling physics topics. This note developed from a discussion at a workshop on ``Electromagnetic Probes of Fundamental Physics,'' in Erice, Italy, Oct. 16-21, 2001.