QCD equation of state with 2+1 flavors of improved staggered quarks

TL;DR

This paper presents lattice QCD calculations of thermodynamic properties like the interaction measure, pressure, and energy density for 2+1 flavor QCD using improved staggered quarks and gauge actions, at finite temperature.

Contribution

It provides new results for QCD thermodynamics with improved lattice actions and physical quark masses, extending previous studies to different lattice spacings and quark mass ratios.

Findings

Interaction measure, pressure, and energy density results for N_t=4 and 6 lattices.

Use of improved staggered quarks and gauge actions enhances accuracy.

Thermodynamic quantities calculated with the integral method.

Abstract

We report results for the interaction measure, pressure and energy density for nonzero temperature QCD with 2+1 flavors of improved staggered quarks. In our simulations we use a Symanzik improved gauge action and the Asqtad $O(a^2)$ improved staggered quark action for lattices with temporal extent $N_t=4$ and 6. The heavy quark mass $m_s$ is fixed at approximately the physical strange quark mass and the two degenerate light quarks have masses $m_{ud}\approx0.1 m_s$ or $0.2 m_s$. The calculation of the thermodynamic observables employs the integral method where energy density and pressure are obtained by integration over the interaction measure.