Chiral Condensate in Holographic QCD with Baryon Density

TL;DR

This paper investigates the behavior of the chiral condensate in dense baryonic matter using a holographic QCD model, revealing phase-dependent minima and classifying condensate behavior at high densities.

Contribution

It introduces a method to calculate the chiral condensate via world-sheet instantons in the Sakai-Sugimoto model, analyzing its behavior across different phases and densities.

Findings

Chiral condensate exhibits a minimum at certain baryon densities.

In the deconfined phase, three types of condensate behavior are identified.

Results align with QCD expectations at low but high densities.

Abstract

We consider the chiral condensate in the baryonic dense medium using the generalized Sakai-Sugimoto model. It is defined as the vacuum expectation value of open Wilson line that is proposed to be calculated by use of the area of world-sheet instanton. We evaluate it in confined as well as deconfined phase. In both phases, the chiral condensate has a minimum as a function of baryon density. In the deconfined phase, taking into account the chiral symmetry restoration, we classify the behavior of chiral condensate into three types. One can set the parameter of the theory such that the results, in low but sufficiently higher density, is in agreement with the expectation from QCD.