Thermodynamics of [formula omitted]-flavor strongly interacting matter at nonzero isospin

Rainer Stiele,Eduardo S Fraga,Jürgen Schaffner-Bielich

doi:10.1016/j.physletb.2013.12.053

Abstract

We investigate the phase structure of strongly interacting matter at non-vanishing isospin before the onset of pion condensation in the framework of the unquenched Polyakov–Quark-Meson model with 2+1 quark flavors. We show results for the order parameters and all relevant thermodynamic quantities. In particular, we obtain a moderate change of the pressure with isospin at vanishing baryon chemical potential, whereas the chiral condensate decreases more appreciably. We compare the effective model to recent lattice data for the decrease of the pseudo-critical temperature with the isospin chemical potential. We also demonstrate the major role played by the value of the pion mass in the curvature of the transition line, and the need for lattice results with a physical pion mass. Limitations of the model at nonzero chemical potential are also discussed.

Highlights

The thermodynamics of strongly interacting matter under extreme conditions plays a major role in the understanding of the physical scenario shortly after the Big Bang [1, 2], in the outcome of high-energy heavy ion collisions [3], in the mechanism of supernovae explosions [4], and in the structure of compact stars [5, 6]
The impact of the quark mass on the deconfining critical temperature at nonzero isospin was investigated in Refs. [17, 18], using a framework that combines chiral perturbation theory to describe the low-energy sector with the phenomenological fuzzy bag model for high energies, showing that quark masses play a relevant role
We compare the decrease of the pseudo-critical temperature with isospin chemical potential to recent lattice data to test the model in its extension to nonzero isospin density

Summary

Introduction

The thermodynamics of strongly interacting matter under extreme conditions plays a major role in the understanding of the physical scenario shortly after the Big Bang [1, 2], in the outcome of high-energy heavy ion collisions [3], in the mechanism of supernovae explosions [4], and in the structure of compact stars [5, 6]. In this work we investigate the phase structure of strongly interacting matter at non-vanishing isospin before the onset of pion condensation in the framework of the Polyakov–Quark-Meson model with 2 + 1 quark fla-

Results

Conclusion