Instanton-induced crossover in dense QCD

TL;DR

This paper investigates how instantons influence the chiral phase transition in dense three-flavor QCD, modeling the instanton ensemble as a weakly interacting plasma and analyzing its effects using renormalization group techniques.

Contribution

It introduces a novel description of the instanton ensemble as a weakly interacting plasma and explores its role in the chiral phase transition at high density.

Findings

Instanton ensemble behaves as a screened, unpaired plasma.

Chiral condensate is proportional to instanton density.

Transition resembles a Berezinskii-Kosterlitz-Thouless transition.

Abstract

We study the properties of an instanton ensemble in three-flavor dense QCD which can be regarded as an instanton plasma weakly interacting by exchanging the eta' mesons. Based on this description, we explore the chiral phase transition induced by the instanton ensemble at high baryon density in analogy with the Berezinskii-Kosterlitz-Thouless transition. Using the renormalization group approach, we show that the instanton ensemble always behaves as a screened and unpaired plasma. We also demonstrate that the chiral condensate in dense QCD is proportional to the instanton density.