Polarization properties of the quark-gluon medium

TL;DR

This paper explores the polarization-induced collective properties of the quark-gluon medium using macroscopic QCD equations, analyzing phenomena like Cherenkov gluons and wake effects, and compares theoretical predictions with experimental data.

Contribution

It introduces a macroscopic QCD framework to describe polarization effects in the quark-gluon medium and analyzes the medium's stability and chromopermittivity based on experimental comparisons.

Findings

Large chromopermittivity at RHIC energies

Medium modes are unstable according to dispersion equations

Cosmic ray data suggest smaller chromopermittivity at higher energies

Abstract

Collective properties of the quark-gluon medium induced by its polarization are described by macroscopic QCD equations. The parton currents traversing it lead to emission of Cherenkov gluons, the wake effect and the transition radiation. Comparison with experimental data of RHIC reveals large value of the chromopermittivity of the medium while cosmic ray data at higher energies (close to LHC) favor much smaller values. The dispersion equations show that the proper modes of the medium are unstable.