Parton energy loss and momentum broadening at NLO in high temperature QCD plasmas

TL;DR

This paper reviews a perturbative approach to jet energy loss and momentum broadening in high-temperature quark-gluon plasmas, incorporating next-to-leading order calculations and recent theoretical advances.

Contribution

It introduces a kinetic framework for jet propagation in QCD plasmas, including NLO corrections and Wilson line techniques for lattice measurements.

Findings

NLO kinetic equations for parton transport are developed.

Wilson line correlators enable lattice calculations of momentum broadening.

Recent theoretical developments simplify the calculation of soft gluonic contributions.

Abstract

We present an overview of a perturbative-kinetic approach to jet propagation, energy loss, and momentum broadening in a high temperature quark-gluon plasma. The leading-order kinetic equations describe the interactions between energetic jet-particles and a non-abelian plasma, consisting of on-shell thermal excitations and soft gluonic fields. These interactions include 2<->2 scatterings, collinear bremsstrahlung, and drag and momentum diffusion. We show how the contribution from the soft gluonic fields can be factorized into a set of Wilson line correlators on the light cone. We review recent field-theoretical developments, rooted in the causal properties of these correlators, which simplify the calculation of the appropriate Wilson lines in thermal field theory. With these simplifications lattice measurements of transverse momentum broadening have become possible, and the kinetic equations describing parton transport have been extended to next-to-leading order in the coupling g.