Jet Quenching in Thin Quark-Gluon Plasmas I: Formalism

TL;DR

This paper develops a formalism to analyze jet quenching effects in thin quark-gluon plasmas, focusing on the angular distribution modifications due to rescattering and interference effects in nuclear collisions.

Contribution

It introduces a systematic method to compute gluon angular distributions considering multiple rescatterings in thin plasmas, highlighting deviations from standard evolution models.

Findings

Angular distribution differs from DGLAP and classical cascade models.

Power law scaling of angular distribution with rescattering number.

Estimates of energy loss as a function of plasma thickness.

Abstract

The modification and amplification of the gluon angular distribution produced along with hard jets in nuclear collisions is computed. We consider the limit of a thin quark-gluon plasma, where the number of rescatterings of the jet and gluons is small. The focus is on jet quenching associated with the formation of highly off-shell partons in hard scattering events involving nuclei. The interference between the initial hard radiation amplitude, the multiple induced Gunion-Bertsch radiation amplitudes, and gluon rescattering amplitudes leads to an angular distribution that differs considerably from both the standard DGLAP evolution and from the classical limit parton cascading. The cases of a single and double rescattering are considered in detail, and a systematic method to compute all matrix elements for the general case is developed. A simple power law scaling of the angular distribution with increasing number of rescatterings is found and used for estimates of the fractional energy loss as a function of the plasma thickness.