Photon dispersion relations in $A_0$-background

TL;DR

This paper computes photon dispersion relations in a quark-gluon plasma with a constant color background, revealing stable modes with gaps and frequency shifts due to the background acting as an imaginary chemical potential.

Contribution

It provides the first calculation of photon dispersion relations considering a non-zero color background in a quark-gluon plasma.

Findings

Both transversal and longitudinal photon modes are excited.

Modes have a gap at low momenta and are stable at high temperature.

Background fields reduce photon frequencies similar to chemical potentials.

Abstract

We calculate the photon dispersion relations generated by the quark loop in a quark-gluon plasma with the color $A_0$ background condensate $A_0^c = A_0^{c3} + A_0^{c8}$ = const. It is found that both transversal and longitudinal modes are exited. They have a gap at low momenta and are stable in high temperature approximation. The background fields act as imaginary chemical potentials and decrease the photon frequencies compared to the case of zero background. The comparison with QED plasma with chemical potential is discussed.