Jet-hadron correlations in STAR

TL;DR

This paper uses advanced jet reconstruction techniques in heavy-ion collisions to study how jets are modified by the medium, revealing broadening, softening, and yield redistribution of jet fragments.

Contribution

It presents a systematic analysis of jet-hadron correlations in Au-Au collisions, demonstrating medium-induced modifications to jet structure at high energies.

Findings

Jets are broadened and softened in the medium.

High-pT suppression is compensated by low-pT enhancement.

Results indicate significant jet-medium interactions.

Abstract

Advancements in full jet reconstruction have made it possible to use jets as triggers in azimuthal angular correlations to study the modification of hard-scattered partons in the medium created in ultrarelativistic heavy-ion collisions. This increases the range of parton energies accessible in these analyses and improves the signal-to-background ratio compared to dihadron correlations. Results of a systematic study of jet-hadron correlations in central Au-Au collisions at sqrt(s_NN) = 200 GeV are indicative of a broadening and softening of jets which interact with the medium. Furthermore, jet-hadron correlations suggest that the suppression of the associated hadron yield at high-pT is balanced in large part by low-pT enhancement.