Thermal Transitions in Domain Wall AdS/QCD

TL;DR

This paper investigates thermal phase transitions in a Domain Wall AdS/QCD model, revealing how quark mass, confinement, and chiral symmetry breaking are interconnected through holographic dualities and phase transition types.

Contribution

It introduces a novel holographic model with a discontinuous mass profile to study thermal transitions, including meson melting and chiral symmetry restoration, with insights into NJL interactions.

Findings

Massive quarks undergo second order meson melting transition.

Confinement induces a first order chiral symmetry restoration.

NJL interactions allow separation of confinement and chiral scales.

Abstract

We study thermal transitions in a Domain Wall AdS/QCD model. The model is based on the D5/probe D7 system with a discontinuous mass profile which restricts chiral fermions to 3+1 dimensional domain walls. Fluctuations on the domain wall are dual to the quark mass and condensate and reveal the relation between domain wall separation and the quark mass. The massive quarks exhibit a second order thermal, meson melting transition. Witten's multi-trace prescription can be used to interpret these configurations as having a dynamical mass from a Nambu-Jona-Lasinio interaction - here the transition is first order. Confinement can be introduced into the gauge sector by compactifying one direction of the D5. Compactification induces chiral symmetry breaking and there is a first order thermal restoration transition. If an NJL interaction is also introduced then the confinement and chiral symmetry breaking scales can be separated.