Constraints on the Jet-Medium Coupling from Measurements at RHIC and LHC

TL;DR

This paper compares different jet-energy loss models to experimental data from RHIC and LHC, highlighting the importance of medium flow and non-linear effects, and finds that current models are insensitive to jet-path dependence.

Contribution

It introduces an extended jet-energy loss model coupled with hydrodynamic and parton cascade backgrounds, emphasizing the role of realistic medium effects in jet quenching.

Findings

High-pT elliptic flow requires realistic medium flow fields.

Results are similar between hydrodynamic and parton cascade backgrounds.

Current models are insensitive to jet-path dependence.

Abstract

The measured data on the nuclear modification factor for pions and reconstructed jets as well as on the high-pT elliptic flow at RHIC and LHC energies are compared to results from a linear pQCD and a highly non-linear hybrid AdS holographic model of jet-energy loss. We find that the high-pT ellitic flow requires to include realistic medium transverse flow fields and a jet-medium coupling including the effects of the energy of the jet, the temperature of the bulk medium, and non-equilibrium effects close to the phase transition. We extend our jet-energy loss model that is coupled to state-of-the-art hydrodynamic prescriptions to backgrounds generated by the parton cascade BAMPS. We demonstrate that the results for the hydrodynamic and the parton-cascade backgrounds show a remarkable similarity. Unfortunately, the results for both the pion and a parton-jet nuclear modification factor are insensitive to the jet-path dependence of the models considered.