Phase diagram of a generalized Stephanov model for finite-density QCD

TL;DR

This paper investigates how modifying the measure in a random matrix model for finite-density QCD affects its phase diagram, revealing a new phase with spontaneous charge-conjugation breaking at large deformations.

Contribution

It introduces a generalized Stephanov model with a trace deformation and analyzes its phase structure, highlighting the impact of the measure on qualitative features.

Findings

Small deformation preserves the original phase diagram.

Large deformation induces an exotic phase with charge-conjugation breaking.

The measure's role is crucial for qualitative features of the model.

Abstract

We solve a random matrix model for QCD at finite chemical potential, obtained by generalizing the Stephanov model by modifying the random-matrix integration measure with a one-parameter trace deformation. This allows one to check how important the integration measure is for the qualitative features of random matrix models, as well as to test the robustness and universality of the qualitative picture of the original model. While for a small trace deformation the phase diagram is identical to that of the Stephanov model, for a large deformation an exotic phase with spontaneous charge-conjugation breaking appears.