Jet-hadron correlations in STAR

TL;DR

This paper discusses the use of jet-hadron correlations in STAR to study how jets are modified by the quark-gluon plasma, revealing broadening and softening effects, and explores future analyses involving event plane dependence.

Contribution

It introduces the application of reconstructed jet-hadron correlations in heavy-ion collisions to investigate jet quenching and medium effects, extending beyond traditional dihadron studies.

Findings

Jets show broadening and softening in the medium

Jets in 2+1 correlations are relatively unmodified

Initial results on event plane dependence indicate measurement challenges

Abstract

In recent years, the study of dihadron correlations has been one of the primary methods used to investigate the propagation and modification of hard-scattered partons through the QGP. Due to recent advances in jet-finding algorithms, it is now possible to use reconstructed jets in these correlation studies, extending the kinematic reach compared to dihadron analyses. The results of the jet-hadron correlation analysis indicate a broadening and softening of jets that interact with the medium. Jet-hadron correlations can also be used to assess the systematics of other jet-like correlation analyses, such as 2+1 correlations. It is shown that the jets selected in 2+1 correlations are relatively unmodified. Future work will include an analysis of jet-hadron correlations with respect to the event plane to measure the pathlength dependence of parton energy loss. The first steps in this analysis indicate that complications arise when calculating the event plane in the presence of a jet as well as in calculating jet v2. The data analyzed were collected by the STAR detector in sqrt(s_NN) = 200 GeV Au-Au collisions at the Relativistic Heavy Ion Collider (RHIC).