Quark-gluon plasma speed of sound in magnetic field

TL;DR

This study uses a non-perturbative Field Correlators method to analyze how a magnetic field influences the speed of sound in quark-gluon plasma, revealing it exceeds the conformal limit at high magnetic fields but remains negligible in current experiments.

Contribution

It provides the first non-perturbative analysis of the magnetic field's effect on the speed of sound in quark-gluon plasma at high temperatures.

Findings

Speed of sound exceeds 1/3 at high magnetic fields.

At high temperatures, the speed of sound approaches the conformal limit.

Magnetic field effects are negligible in current heavy-ion collision experiments.

Abstract

A non-perturbative method of Field Correlators (FCM) is applied to study speed of sound in quark-gluon plasma at temperatures above the deconfinement transition 1<T/T_c<3 (Tc=160 MeV) under a uniform magnetic field up to eB ~ 1 GeV^2. The speed of sound in N_f=2+1 QCD quark-gluon plasma is found to exceed the conformal limit (1/3) at very large magnetic field strengths eB>0.5 GeV^2. At large temperatures, the speed of sound tends to the conformal limit; low-temperature behavior demonstrates inverse magnetic catalysis. The effect of magnetic field on the speed of sound in quark-gluon plasma is found to be negligible in any existing Heavy Ion Collision experiment, including \sqrt{s_{NN}}=5.02 TeV Pb-Pb collisions at LHC.