Sensitivity of the Jet Quenching Observables to the Temperature Dependence of the Energy Loss

TL;DR

This paper investigates how the temperature dependence of parton energy loss in quark-gluon plasma influences jet quenching observables, emphasizing the importance of energy loss near the critical temperature for explaining experimental data.

Contribution

It demonstrates that the temperature profile of energy loss, especially around the critical temperature, is crucial for understanding jet quenching phenomena and related observables.

Findings

Energy loss near $T_c$ explains large elliptic flow.

Quark-gluon conversion significantly affects suppression ratios.

Lattice QCD-based equations of state improve model accuracy.

Abstract

The quenching of minijet (particles with $p_T>> T, \Lambda_{QCD}$) in ultra-relativistic heavy-ion collisions has been one of the main prediction and discovery at RHIC. We analyze the correlation between different observables like the nuclear modification factor $\Rapt$, the elliptic flow and the ratio of quark to gluon suppressions. We show that the temperature (or entropy density) dependence of the in-medium energy loss strongly affects the relation among these observables. In particular the large elliptic flow and the nearly equal $\Rapt$ of quarks and gluons can be accounted for only if the energy loss occurs mainly around $T_c$ and the $q\leftrightarrow g$ conversion is significant. The use of an equation of state fitted to lattice QCD calculations, slowing down the cooling as $T \to T_c$, seems to contribute to both the enhancement of $v_2$ and the efficiency of the conversion mechanism.