Energy loss at NLO in a high-temperature Quark-Gluon Plasma

TL;DR

This paper extends the kinetic equations for jet energy loss in a high-temperature quark-gluon plasma to next-to-leading order, incorporating semi-collinear emissions and providing a framework for NLO transport coefficients.

Contribution

It introduces a consistent NLO description of wider-angle bremsstrahlung and relates transport coefficients to Wilson line operators for computation.

Findings

NLO corrections to jet energy loss are formulated.

Semi-collinear emissions are incorporated into the kinetic framework.

A method for computing transport coefficients using Euclidean formalism is proposed.

Abstract

We present an extension of the Arnold-Moore-Yaffe kinetic equations for jet energy loss to NLO in the strong coupling constant. A novel aspect of the NLO analysis is a consistent description of wider-angle bremsstrahlung (semi-collinear emissions), which smoothly interpolates between 2<->2 scattering and collinear bremsstrahlung. We describe how many of the ingredients of the NLO transport equations (such as the drag coefficient) can be expressed in terms of Wilson line operators and can be computed using a Euclidean formalism or sum rules, both motivated by the analytic properties of amplitudes at light-like separations. We conclude with an outlook on the computation of the shear viscosity at NLO.