Azimuthal Jet Tomography at RHIC and LHC

TL;DR

This paper compares a generic jet-energy loss model, interpolating between pQCD and holographic approaches, to RHIC and LHC data on high-p_T pion suppression and elliptic flow, exploring energy-loss fluctuations and temperature dependencies.

Contribution

It introduces a broad class of jet-energy loss models that fit current data, contrasting with previous models that are inconsistent with LHC results.

Findings

AdS/CFT model with temperature-independent coupling is inconsistent with LHC data.

A class of models with $dE/dx= \, \kappa(T) x^z T^{2+z}$ can fit data for various $z$ and $\, \kappa(T)$.

Energy-loss fluctuations and temperature dependence significantly affect jet quenching predictions.

Abstract

Results based on a generic jet-energy loss model that interpolates between running coupling pQCD-based and AdS/CFT-inspired holographic prescriptions are compared to recent data on the high-p_T pion nuclear modification factor and the high-p_T elliptic flow in nuclear collisions at RHIC and LHC. The jet-energy loss model is coupled to various (2+1)d (viscous hydrodynamic) fields. The impact of energy-loss fluctuations is discussed. While a previously proposed AdS/CFT jet-energy loss model with a temperature-independent jet-medium coupling is shown to be inconsistent with the LHC data, we find a rather broad class of jet-energy independent energy-loss models $dE/dx= \kappa(T) x^z T^{2+z}$ that can account for the current data with different temperature-dependent jet-medium couplings $\kappa(T)$ and path-length dependence exponents of $0\le z \le 2$.