Chiral and Critical Behavior in Strong Coupling QCD

TL;DR

This study investigates the critical behavior of strongly coupled lattice QCD at finite temperature, confirming the O(2) universality class and providing evidence for chiral singularities, while highlighting challenges in matching quark mass dependence with chiral perturbation theory.

Contribution

The paper demonstrates the critical behavior of strongly coupled lattice QCD using a cluster algorithm, confirming the O(2) universality class and analyzing chiral singularities and quark mass dependence.

Findings

Finite temperature chiral phase transition belongs to O(2) universality class.

Clear evidence for chiral singularities predicted by chiral perturbation theory.

Difficulty in reconciling quark mass dependence with chiral perturbation theory.

Abstract

We use a cluster algorithm to study the critical behavior of strongly coupled lattice QCD in the chiral limit. We show that the finite temperature chiral phase transition belongs to the O(2) universality class as expected. When we compute the finite size effects of the chiral susceptibility in the low temperature phase close to the transition, we find clear evidence for chiral singularities predicted by chiral perturbation theory (ChPT). On the other hand it is difficult to reconcile the quark mass dependence of various quantities near the chiral limit with ChPT.