Full resummation analysis of jet quenching and tests of the QCD Equation of State

TL;DR

This paper improves the theoretical calculation of jet quenching in heavy ion collisions by resumming all terms in the opacity expansion, leading to more accurate extraction of QCD medium properties and better comparison with lattice results.

Contribution

It introduces an improved numerical method for medium-induced gluon spectrum calculation that surpasses previous approximations in jet quenching analysis.

Findings

Significant differences in medium parameters when using improved resummation.

Improved agreement with lattice QCD results.

Highlighting the importance of beyond-Gaussian and first-order opacity approximations.

Abstract

Jet quenching has become a fundamental tool to study the hot QCD matter produced in heavy ion collisions. While important theoretical and experimental advances have been made in the last two decades, the extraction of the medium properties and the comparison with finite temperature QCD is still particularly worrisome. In this work we show that improvements in the calculation of the medium-induced gluon spectrum are required for a correct extraction of the parameters without temperature issues. In particular, we employ an improved numerical implementation of multiple hard scatterings that resums all terms in the opacity expansion beyond the Gaussian approximation. We find significant differences in the extracted medium parameters when comparing with two of the most used approximations in phenomenological analyses to date, the first order opacity expansion and the Gaussian approximation. We also make a first attempt to compare the extracted medium parameters with lattice results.