The equation of state in lattice QCD: with physical quark masses towards the continuum limit

TL;DR

This paper computes the QCD equation of state at zero chemical potential using lattice simulations with physical quark masses, approaching the continuum limit by employing different lattice spacings and improved actions.

Contribution

It provides the first detailed determination of the QCD equation of state with physical quark masses near the continuum limit using multiple lattice spacings.

Findings

Pressure and energy density as functions of temperature.

Quark number susceptibilities and speed of sound results.

Agreement with previous theoretical predictions at high temperatures.

Abstract

The equation of state of QCD at vanishing chemical potential as a function of temperature is determined for two sets of lattice spacings. Coarser lattices with temporal extension of N_t=4 and finer lattices of N_t=6 are used. Symanzik improved gauge and stout-link improved staggered fermionic actions are applied. The results are given for physical quark masses both for the light quarks and for the strange quark. Pressure, energy density, entropy density, quark number susceptibilities and the speed of sound are presented.