Circularly polarized photon emission from magnetized chiral plasmas

TL;DR

This paper studies how magnetic fields and chemical potentials in a quark-gluon plasma affect the emission of circularly polarized photons, suggesting polarization as a probe for plasma properties in heavy-ion collisions.

Contribution

It introduces the impact of quark-number and chiral chemical potentials on polarized photon emission rates in magnetized plasmas, highlighting their potential as experimental observables.

Findings

Nonzero quark-number chemical potential enhances one polarization.

Chiral chemical potential causes spatial asymmetry in emission.

Polarized photon emission can characterize quark-gluon plasma properties.

Abstract

We investigate the emission of circularly polarized photons from a magnetized quark-gluon plasma with nonzero quark-number and chiral charge chemical potentials. These chemical potentials qualitatively influence the differential emission rates of circularly polarized photons. A nonzero net electric charge density, induced by quark-number chemical potentials, enhances the overall emission of one circular polarization over the other, while a nonzero chiral charge density introduces a spatial asymmetry in the emission with respect to reflection in the transverse plane. The signs of the electrical and chiral charge densities determine which circular polarization dominates overall and whether the emission preferentially aligns with or opposes the magnetic field. Based on these findings, we propose that polarized photon emission is a promising observable for characterizing the quark-gluon plasma produced in heavy-ion collisions.