Beam-energy and system-size dependence of the CME

TL;DR

This paper estimates how the Chiral Magnetic Effect (CME) varies with collision energy and system size in heavy-ion collisions, predicting a significant weakening at LHC energies and a sharp decline at lower energies, while also proposing a transport model to study background effects.

Contribution

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

Findings

CME expected to be ~20 times weaker at LHC than at RHIC

CME should sharply vanish above the top SPS energy

A transport model with magnetic field evolution is proposed

Abstract

The energy dependence of the local ${\cal P}$ and ${\cal CP}$ violation in Au+Au and Cu+Cu collisions in a large energy range is estimated within a simple phenomenological model. It is expected that at LHC the Chiral Magnetic effect (CME) will be about 20 times weaker than at RHIC. In the 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.