Separating hard and soft scales in hard processes in a QCD plasma

TL;DR

This paper proposes a framework for analyzing hard processes in a QCD plasma by separating the hard and soft scales, utilizing perturbative QCD for the hard part and AdS/CFT correspondence for the soft part, and estimates the transport coefficient.

Contribution

It introduces a scale separation approach combining perturbative QCD and AdS/CFT insights to study phenomena in a QCD plasma, including an estimate of the transport coefficient.

Findings

Estimation of the transport coefficient $$ in the plasma.

A proposed scale separation framework for hard and soft processes.

Insights into strong coupling effects via AdS/CFT correspondence.

Abstract

We present a picture of hard processes in a hot plasma in terms of the hard scale part of the process, where perturbative QCD should be applicable, and the soft scale part of the process, where we look to the AdS/CFT correspondence for guidance to possible strong effective coupling phenomena. In particular we estimate $\hat{q}$, the transport coefficient, supposing that at soft scales partons in the plasma all cascade to small-$x$-values as indicated by strong coupling SYM theory.