Realistic medium-averaging in radiative energy loss

TL;DR

This paper investigates how realistic transverse expansion in the medium affects jet energy loss and elliptic flow at RHIC and LHC energies, revealing that expansion reduces elliptic flow and influences suppression patterns.

Contribution

It demonstrates that incorporating realistic transverse expansion significantly alters predictions of jet quenching observables within the GLV formalism.

Findings

Transverse expansion reduces high-pT elliptic flow (v2).

Expansion leads to stronger high-pT suppression.

Energy loss fluctuations weaken suppression effects.

Abstract

We present results from a jet energy loss calculation using the Gyulassy-Levai-Vitev (GLV) formalism and bulk medium evolution from the covariant transport model MPC. At both RHIC and LHC energies we find that realistic transverse expansion strongly reduces elliptic flow at high pT compared to calculations with transversely 'frozen' profiles. We argue that this is a generic feature of GLV energy loss. Transverse expansion also leads to stronger high-pT suppression, while fluctuations in energy loss with the location of scattering centers weaken the suppression. But, unlike the reduction of v2, these effects nearly disappear once alpha_s is adjusted to reproduce R_AA in central collisions.