Thermodynamics with 2+1 and 3 Flavors of Improved Staggered Quarks

TL;DR

This paper investigates the phase diagram of finite temperature QCD with multiple quark flavors using improved lattice actions to reduce artifacts and better understand thermodynamic properties.

Contribution

It introduces improved staggered quark actions that diminish lattice artifacts and flavor symmetry breaking, enhancing the accuracy of finite temperature QCD simulations.

Findings

Improved actions lead to lighter pions at transition temperature.

Reduced lattice artifacts improve thermodynamic property estimates.

Preliminary results on multiple lattice sizes are presented.

Abstract

We present preliminary results from exploring the phase diagram of finite temperature QCD with three degenerate flavors and with two light flavors and the mass of the third held approximately at the strange quark mass. We use an order $\alpha_s^2 a^2, a^4$ Symanzik improved gauge action and an order $\alpha_s a^2, a^4$ improved staggered quark action. The improved staggered action leads to a dispersion relation with diminished lattice artifacts, and hence better thermodynamic properties. It decreases the flavor symmetry breaking of staggered quarks substantially, and we estimate that at the transition temperature for an $N_t=8$ to $N_t=10$ lattice {\em all} pions will be lighter than the lightest kaon. Preliminary results on lattices with $N_t=4$, 6 and 8 are presented.