Energy-momentum tensor correlation function in Nf=2+1 full QCD at finite temperature

TL;DR

This study measures the energy-momentum tensor correlation functions in full QCD at finite temperature using the gradient flow method, testing conservation laws and calculating specific heat at a single temperature.

Contribution

It applies the gradient flow method to nonperturbatively renormalize the energy-momentum tensor in full QCD at finite temperature, providing insights into conservation laws and thermodynamic properties.

Findings

Confirmed the conservation law of the energy-momentum tensor.

Validated the linear response relation for entropy density.

Calculated the specific heat from correlation functions.

Abstract

We measure correlation functions of the nonperturbatively renormalized energy-momentum tensor in $N_f=2+1$ full QCD at finite temperature by applying the gradient flow method both to the gauge and quark fields. Our main interest is to study the conservation law of the energy-momentum tensor and to test whether the linear response relation is properly realized for the entropy density. By using the linear response relation we calculate the specific heat from the correlation function. We adopt the nonperturbatively improved Wilson fermion and Iwasaki gauge action at a fine lattice spacing $=0.07$ fm. In this paper the temperature is limited to a single value $T=232$ MeV. The $u$, $d$ quark mass is rather heavy with $m_\pi/m_\rho=0.63$ while the $s$ quark mass is set to approximately its physical value.