The speed of sound and specific heat in the QCD plasma: hydrodynamics, fluctuations and conformal symmetry

TL;DR

This paper investigates the thermodynamic properties of the quenched QCD plasma at high temperatures, focusing on the speed of sound and specific heat, and explores their relation to conformal symmetry in the deconfined phase.

Contribution

It provides continuum limit results for c_s and c_v at 2Tc and 3Tc, highlighting their proximity to conformal symmetry expectations in high-temperature QCD.

Findings

c_s near ideal gas value within 2-sigma

c_v significantly differs from ideal gas

both c_s and c_v compatible with conformal symmetry

Abstract

We report the continuum limits of the speed of sound, c_s, and the specific heat at constant volume, c_v, in quenched QCD at temperatures of 2Tc and 3Tc. At these temperatures, c_s is within 2-sigma of the ideal gas value, whereas c_v differs significantly from the ideal gas. However, both are compatible with results expected in a theory with conformal symmetry. We investigate effective measures of conformal symmetry in the high temperature phase of QCD.