Radiative corrections for factorized jet observables in heavy ion collisions

TL;DR

This paper develops a formalism for understanding how jet substructure observables are affected by the Quark Gluon Plasma in heavy ion collisions, incorporating renormalization and resummation techniques based on an EFT approach.

Contribution

It introduces a renormalization framework for medium structure functions and jet functions, deriving RG equations analogous to BFKL and QCD running, with initial numerical results.

Findings

Medium structure function has UV and rapidity anomalous dimensions.

RG equations correspond to BFKL and QCD coupling running.

Resummation impacts the mean free path of jets in the medium.

Abstract

I look at the renormalization of the medium structure function and a medium induced jet function in a factorized cross section for jet substructure observables in Heavy Ion collisions. This is based on the formalism developed in \cite{Vaidya:2020lih}, which uses an Open quantum system approach combined with the Effective Field Theory(EFT) for forward scattering to derive a factorization formula for jet observables which work as hard probes of a long lived dilute Quark Gluon Plasma(QGP) medium. I show that the universal medium structure function that captures the observable independent physics of the QGP has both UV and rapidity anomalous dimensions that appear due to medium induced Bremsstrahlung. The resulting Renormalization Group(RG) equations correspond to the BFKL equation and the running of the QCD coupling respectively. I present the first results for the numerical impact of resummation using these RG equations on the mean free path of the jet in the medium. I also briefly discuss the prospects of extending this formalism for a short lived dense medium.