QCD chiral phase diagram from weak functional renormalization group

TL;DR

This paper uses a novel weak solution approach to the functional Renormalization Group to study the QCD chiral phase diagram, focusing on quark fluctuations without auxiliary bosonic fields, revealing insights into chiral symmetry breaking at finite temperature and density.

Contribution

It introduces a weak solution method for fRG equations to analyze the QCD chiral phase diagram without dynamical bosonization, emphasizing purely fermionic fluctuations.

Findings

Chiral phase diagram as a function of temperature and baryon chemical potential.

Effects of quark-level fluctuations on chiral symmetry breaking.

Demonstration of a non-analytic behavior in the fRG flow.

Abstract

We investigate the QCD chiral phase transition at finite temperature and finite baryon density using the functional Renormalization Group (fRG). While conventional fRG studies often employ techniques such as dynamical bosonization to regularize divergences, we instead pursue the weak solution of the fRG equations which allows for non-analytic behavior in the flow to compute the pure fermionic potential $V_k(\psi,\bar{\psi})$ within the local potential approximation. This approach enables us to explore the effects of purely quark-level fluctuations on dynamical chiral symmetry breaking without introducing any auxiliary bosonic fields. Based on this framework, we present the resulting chiral phase diagram as a function of temperature and baryon chemical potential.