The speed of sound in QGP and SU(3) Yang-Mills theory

TL;DR

This paper calculates the speed of sound in SU(3) and (2+1)QCD using the Field Correlator Method, revealing a discontinuity at the critical temperature and confirming that it never exceeds one-third, aligning well with lattice data.

Contribution

It introduces a nonperturbative approach to compute the speed of sound in QGP, highlighting a discontinuity at the phase transition and establishing bounds consistent with lattice results.

Findings

Discontinuity in $C_s$ at $T_c$ in SU(3)

$C_s^2$ remains below 1/3 in both theories

Numerical results agree with lattice data

Abstract

The speed of sound $C_{s}$ in the SU(3) and (2+1)QCD is calculated within the Field Correlator Method using the nonperturbative colour magnetic confinement and Polyakov loop interaction in the deconfined region.The resulting $C_{s}$ displays a discontinuity at $T=T_{c}$ in the SU(3) case. It is shown numerically and analytically that $ C^{2}_{s}$ never exceeds $\frac{1}{3}$ both for SU(3) and (2+1) QCD for vanishing chemical potential.A good agreement is found of our numerical results with the corresponding lattice data.