Photoemission with Chemical Potential from QCD Gravity Dual

TL;DR

This paper uses a holographic QCD model to analyze chiral phase transitions at finite chemical potential and temperature, revealing a phase transition line and spectral function features relevant for photon emission.

Contribution

It introduces a gravity dual model for large N QCD to study phase transitions and spectral functions at finite chemical potential and temperature.

Findings

Identifies a line of first-order phase transitions in the phase diagram.

Computes spectral functions and photon emission rates.

Spectral function trace becomes non-monotonic at high chemical potential.

Abstract

We consider a $D4-D8-\bar D8$ brane construction which gives rise to a large N QCD at sufficiently small energies. Using the gravity dual of this system, we study chiral phase transition at finite chemical potential and temperature and find a line of first order phase transitions in the phase plane. We compute the spectral function and the photon emission rate. The trace of the spectral function is monotonic at vanishing chemical potential, but develops some interesting features as the value of the chemical potential is increased.