Classifying the Phases of Gauge Theories by Spectral Density of Probing Chiral Quarks

TL;DR

This paper proposes a spectral density-based method to classify phases of gauge theories with fundamental quarks, revealing a common anomalous phase with broken chiral symmetry across various conditions.

Contribution

It introduces a novel spectral density approach to identify gauge theory phases and provides evidence for a widespread anomalous phase with broken chiral symmetry.

Findings

Existence of a bimodal (anomalous) spectral density phase.

Anomalous phase occurs in deconfined QCD above crossover temperature.

Anomalous phase also appears in zero-temperature systems with many light flavors.

Abstract

We describe our recent proposal that distinct phases of gauge theories with fundamental quarks translate into specific types of low-energy behavior in Dirac spectral density. The resulting scenario is built around new evidence substantiating the existence of a phase characterized by bimodal (anomalous) density, and corresponding to deconfined dynamics with broken valence chiral symmetry. We argue that such anomalous phase occurs quite generically in these theories, including in "real world" QCD above the crossover temperature, and in zero-temperature systems with many light flavors.