On the Ter-Mikaelian and Landau--Pomeranchuk effects for induced soft gluon radiation in a QCD medium

TL;DR

This paper investigates how the polarization of a QCD medium affects induced soft gluon radiation, revealing an analogue of the Ter-Mikaelian effect in QCD that modifies radiation spectra at small transverse momenta.

Contribution

It introduces the QCD analogue of the Ter-Mikaelian effect and analyzes its interplay with the Landau--Pomeranchuk effect in medium-induced gluon radiation.

Findings

Polarization modifies the gluon radiation spectrum at small transverse momenta.

The Ter-Mikaelian effect appears in a different phase space region in QCD compared to QED.

The combined effects influence the radiation pattern of high-energy partons in a medium.

Abstract

The polarization of a surrounding QCD medium modifies the induced gluon radiation spectrum of a high-energy parton at small transverse momenta for a single interaction and for multiple scatterings as well. This effect is an analogue of the Ter-Mikaelian effect in QED, superimposed to the Landau--Pomeranchuk effect, however it appears in QCD in a different phase space region.