Strong and Electromagnetic Forces in Heavy Ion Collisions

TL;DR

This paper investigates how strong and electromagnetic forces influence charged particle spectra in heavy ion collisions, providing new insights into the space-time evolution and nuclear break-up processes, especially in Pb-induced and p+A reactions.

Contribution

It presents new experimental and theoretical results on electromagnetic effects in heavy ion collisions, including for the first time the impact on p+A reactions at LHC energies.

Findings

Electromagnetic forces cause significant distortions in charged pion spectra.

Spectator-induced electromagnetic effects reveal details about collision centrality.

New data on p+A collisions enhance understanding of nuclear break-up.

Abstract

The interplay between the strong and electromagnetic force in high energy nucleus-nucleus collisions was studied experimentally and theoretically in our earlier works. This effect appeared to result in very large distortions in spectra of charged pions produced in the collision. It was also found to bring new, independent information on the space-time evolution of the non-perturbative process of particle production. In this paper, we present our new results on the influence of the spectator-induced electromagnetic force on spectra of charged particles produced in two different Pb-induced reactions. For the first time, we also address the topic of p+A collisions in view of obtaining information about their centrality and nuclear break-up, both subjects being of importance in the context of the new p+A data collected at the LHC.