# Systematic Comparison of Jet Energy-Loss Schemes in a realistic hydrodynamic medium - Nuclear Theory

Abstract: We perform a systematic comparison of three different jet energy-lossapproaches. These include the Armesto-Salgado-Wiedemann scheme based on theapproach of Baier-Dokshitzer-Mueller-Peigne-Schiff and Zakharov BDMPS-Z-ASW,the Higher Twist approach HT and a scheme based on the approach ofArnold-Moore-Yaffe AMY. In this comparison, an identical medium evolutionwill be utilized for all three approaches: not only does this entail the use ofthe same realistic three-dimensional relativistic fluid dynamics RFDsimulation, but also includes the use of identical initial parton-distributionfunctions and final fragmentation functions. We are, thus, in a uniqueposition, not only to isolate fundamental differences between the variousapproaches, but also to make rigorous calculations for different experimentalmeasurements using -state of the art- components. All three approaches arereduced to a version which contains only one free tunable parameter, this isthen related to the well known transport parameter $\hat{q}$. We find that theparameters of all three calculations can be adjusted to provide a gooddescription of inclusive data on $R {AA}$ versus transverse momentum. However,we do observe slight differences in their predictions for the centrality andazimuthal angular dependence of $R {AA}$ vs. $p T$. We also note that the valueof the transport coefficient $\hat{q}$ in the three approaches to describe thedata differs significantly.

Author: Steffen A. Bass, Charles Gale, Abhijit Majumder, Chiho Nonaka, Guang-You Qin, Thorsten Renk, Jörg Ruppert

Source: https://arxiv.org/