Medium induced QCD cascades: broadening and rescattering during branching

TL;DR

This paper investigates how momentum transfer during QCD jet branching affects jet broadening in quark-gluon plasma, highlighting the importance of rescattering and the limitations of common approximations.

Contribution

It introduces a detailed analysis of momentum transfer effects during jet branching and compares different approximation methods in modeling jet evolution in QGP.

Findings

Momentum transfer during branching significantly impacts jet broadening.

The diffusive approximation requires a large jet-quenching parameter to match the BDIM equation.

Gaussian and diffusive approximations have limitations in accurately modeling jet evolution.

Abstract

We study evolution equations describing jet propagation through quark--gluon plasma (QGP). In particular we investigate the contribution of momentum transfer during branching and find that such a contribution is sizeable. Furthermore, we study various approximations, such as the Gaussian approximation and the diffusive approximation to the jet-broadening term. We notice that in order to reproduce the BDIM equation (without the momentum transfer in the branching) the diffusive approximation requires a very large value of the jet-quenching parameter $\hat q$.