Dyson-Schwinger study of chiral density waves in QCD

TL;DR

This study uses Dyson-Schwinger equations to explore inhomogeneous chiral condensates in QCD at finite density, revealing that inhomogeneous phases dominate much of the phase transition region and extend to high chemical potentials.

Contribution

First Dyson-Schwinger analysis of inhomogeneous chiral condensates in QCD, identifying their role in the phase diagram at finite density and temperature.

Findings

Inhomogeneous phase covers major part of the spinodal region.

Triple point coincides with the critical point of homogeneous phases.

Inhomogeneous phase extends to high chemical potentials at zero temperature.

Abstract

The formation of inhomogeneous chiral condensates in QCD matter at nonzero density and temperature is investigated for the first time with Dyson-Schwinger equations. We consider two massless quark flavors in a so-called chiral density wave, where scalar and pseudoscalar quark condensates vary sinusoidally along one spatial dimension. We find that the inhomogeneous region covers the major part of the spinodal region of the first-order phase transition which is present when the analysis is restricted to homogeneous phases. The triple point where the inhomogeneous phase meets the homogeneous phases with broken and restored chiral symmetry, respectively, coincides, within numerical accuracy, with the critical point of the homogeneous calculation. At zero temperature, the inhomogeneous phase seems to extend to arbitrarily high chemical potentials, as long as pairing effects are not taken into account.