On the QCD Ground State at High Density

TL;DR

This paper analyzes the ground states of QCD at high densities, revealing color-flavor structures, symmetry breaking patterns, and potential phenomenological implications using Dyson-Schwinger equations.

Contribution

It provides a detailed characterization of QCD ground states at high density, including color-flavor structures and symmetry breaking, using weak-coupling Dyson-Schwinger equations.

Findings

In two-flavor QCD, SU(3) color breaks to SU(2).

In three-flavor QCD, color-flavor locking (CFL) occurs with lowest energy.

Identifies flat directions in the potential where gauge symmetry and parity are violated.

Abstract

We investigate the possible ground states of QCD at asymptotic densities, where the theory is expected to exhibit color superconductivity. We characterize the color-flavor structure of possible diquark condensates, and find those that are energy extrema by solving the weak-coupling Dyson-Schwinger equations, including Landau damping and the Meissner effect. We show that, as previously anticipated, in the two flavor case the vacuum breaks SU(3) color to SU(2) and in the three flavor case the vacua with color-flavor locking (CFL) have the lowest energy. We identify a number of relatively flat directions in the potential along which the pattern of gauge symmetry breaking changes and parity is violated. We discuss possible phenomenological consequences of our results.