Back-reaction of Non-supersymmetric Probes: Phase Transition and Stability

TL;DR

This paper studies the effects of back-reaction from non-supersymmetric probe branes in a holographic model, revealing a phase transition and stability features due to the back-reaction at finite temperature.

Contribution

It provides an analytical solution for back-reacted backgrounds with non-supersymmetric probes and explores the resulting phase transition and stability in the dual field theory.

Findings

Back-reaction breaks conformal invariance and introduces a dimension 6 operator.

A chiral phase transition appears at finite temperature due to back-reaction.

The system remains stable beyond the probe approximation.

Abstract

We consider back-reaction by non-supersymmetric D7/anti-D7 probe branes in the Kuperstein-Sonnenschein model at finite temperature. Using the smearing technique, we obtain an analytical solution for the back-reacted background to leading order in N_f/N_c. This back-reaction explicitly breaks the conformal invariance and introduces a dimension 6 operator in the dual field theory which is an irrelevant deformation of the original conformal field theory. We further probe this back-reacted background by introducing an additional set of probe brane/anti-brane. This additional probe sector undergoes a chiral phase transition at finite temperature, which is absent when the back-reaction vanishes. We investigate the corresponding phase diagram and the thermodynamics associated with this phase transition. We also argue that additional probes do not suffer from any instability caused by the back-reaction, which suggests that this system is stable beyond the probe limit.