Variation of jet quenching from RHIC to LHC and thermal suppression of QCD coupling constant

TL;DR

This paper analyzes jet quenching data from RHIC and LHC to study how the QCD coupling constant behaves in quark-gluon plasma, revealing its suppression at higher energies.

Contribution

It presents a joint analysis of jet quenching data incorporating running coupling effects, highlighting the suppression of the QCD coupling in LHC-produced plasma.

Findings

QCD coupling constant is suppressed in LHC quark-gluon plasma.

Slow variation of $R_{AA}$ from RHIC to LHC is explained by coupling suppression.

Joint analysis with radiative and collisional energy loss models.

Abstract

We perform a joint jet tomographic analysis of the data on the nuclear modification factor $R_{AA}$ from PHENIX at RHIC and ALICE at LHC. The computations are performed accounting for radiative and collisional parton energy loss with running coupling constant. Our results show that the observed slow variation of $R_{AA}$ from RHIC to LHC indicates that the QCD coupling constant is suppressed in the quark-gluon plasma produced at LHC.