The impact of the medium and the jet-medium coupling on jet measurements at RHIC and LHC

TL;DR

This study compares jet-energy loss models coupled with hydrodynamic backgrounds to experimental data at RHIC and LHC, highlighting the importance of jet-medium coupling and flow effects on high-pT elliptic flow.

Contribution

It extends a perturbative QCD jet-energy loss model to include realistic medium backgrounds and flow fields, analyzing their effects on jet quenching observables.

Findings

Jet-medium coupling and flow fields are crucial for describing high-pT elliptic flow.

Similar results are obtained with different background models, emphasizing the role of coupling and flow.

Background medium and flow influence jet quenching measurements at high transverse momentum.

Abstract

We compare a perturbative QCD-based jet-energy loss model to the measured data of the pion nuclear modification factor and the high-pT elliptic flow at RHIC and LHC energies. This jet-energy loss model (BBMG) is currently coupled to state-of-the-art hydrodynamic descriptions. We report on a model extension to medium backgrounds generated by the parton cascade BAMPS. In addition, we study the impact of realistic medium transverse flow fields and a jet-medium coupling which includes the effects of the jet energy, the temperature of the bulk medium, and non-equilibrium effects close to the phase transition. By contrasting the two different background models, we point out that the description of the high-pT elliptic flow for a non-fluctuating medium requires to include such a jet-medium coupling and the transverse flow fields. While the results for both medium backgrounds show a remarkable similarity, there is an impact of the background medium and the background flow on the high-pT elliptic flow.