Transverse momentum broadening at NLO and QCD evolution of $\hat q$

TL;DR

This paper presents a comprehensive NLO calculation of transverse momentum broadening in high-energy nuclear collisions, establishing QCD factorization and evolution of the jet transport parameter $t$, crucial for understanding parton interactions in nuclear matter.

Contribution

It provides the first complete NLO calculation of transverse momentum broadening and derives the QCD evolution equation for the quark-gluon correlation function, advancing theoretical understanding.

Findings

QCD factorization holds at one-loop level for multiple scattering.

Derived the QCD evolution equation for the quark-gluon correlation function.

Identified the energy dependence of the jet transport parameter t.

Abstract

Within the framework of a high-twist approach, we show the first complete next-to-leading order calculation of transverse momentum broadening in semi-inclusive deeply inelastic $e+A$ scattering and Drell-Yan dilepton production in $p+A$ collisions. We demonstrate at one-loop level how QCD factorization holds for multiple scattering in nuclear medium, and the university of the associated quark-gluon correlation function. Our calculation also identifies QCD evolution equation for the quark-gluon correlation function, which determines the QCD factorization scale and energy dependence of jet transport parameter $\hat q$.