Energy dependence of the chiral magnetic effect in expanding holographic plasma

TL;DR

This paper uses holographic models to study how the chiral magnetic effect varies with energy in an expanding quark-gluon plasma, revealing that higher energies generally enhance the observable CME signal.

Contribution

It provides a novel holographic analysis of the CME in expanding plasma across different energies, incorporating time-dependent magnetic fields and axial charges.

Findings

Time-integrated CME current tends to increase with initial energy.

Expansion dilutes the CME current over time.

Higher collision energies may improve CME observability.

Abstract

Based on a holographic far-from-equilibrium calculation of the chiral magnetic effect~(CME) in an expanding quark gluon plasma, we study collisions at various energies. We compute the time evolution of the CME current in the presence of a time-dependent axial charge density and subject to a time-dependent magnetic field. The plasma expansion leads to a dilution of the CME current. We study distinct combinations of how the initial magnetic field and initial axial charge behave with changing initial energy as proposed in previous literature. Most scenarios we consider lead to an increasing time-integrated CME current, when increasing the initial energy. This would make it more likely to observe the CME at higher collision energies.