The Chiral Magnetic Effect: Beam-energy and system-size dependence

TL;DR

This paper investigates how the chiral magnetic effect varies with collision energy and system size in heavy-ion collisions, predicting a significant decrease at higher energies and a sharp vanishing at lower energies, using phenomenological and transport models.

Contribution

It introduces a phenomenological model for energy dependence of the CME and a transport model including magnetic field evolution to analyze background effects.

Findings

CME weakens by a factor of 20 at LHC compared to RHIC

CME vanishes above the top SPS energy

Transport model elucidates background effects

Abstract

We consider the energy dependence of the local ${\cal P}$ and ${\cal CP}$ violation in Au+Au and Cu+Cu collisions over a large energy range within a simple phenomenological model. It is expected that at LHC the chiral magnetic effect will be about 20 times weaker than at RHIC. At lower energy range this effect should vanish sharply at energy somewhere above the top SPS one. To elucidate CME background effects a transport model including magnetic field evolution is put forward.