Azimuthal Correlations with High-pT Multi-Hadron Cluster Triggers in Au+Au Collisions at sqrt(sNN) = 200 GeV

TL;DR

This study investigates azimuthal correlations using multi-hadron clusters as triggers in Au+Au collisions at 200 GeV to better understand parton energy loss and jet fragmentation.

Contribution

It introduces a novel multi-hadron cluster trigger method to improve constraints on initial parton energy in heavy-ion collisions.

Findings

Multi-hadron triggers provide enhanced sensitivity to jet energy loss.

Comparison with Pythia suggests medium modifications to jet fragmentation.

Results indicate potential for improved understanding of parton energy loss mechanisms.

Abstract

Di-hadron correlation measurements have been used to probe di-jet production in collisions at RHIC. A strong suppression of the away-side high-pT yield in these measurements is direct evidence that high-pT partons lose energy as they traverse the strongly interacting medium. However, since the momentum of the trigger particle is not a good measure of the jet energy, azimuthal di-hadron correlations have limited sensitivity to the shape of the fragmentation function. We explore the possibility to better constrain the initial parton energy by using clusters of multiple high-pT hadrons in a narrow cone as the 'trigger particle' in the azimuthal correlation analysis. We present first results from this analysis of multi-hadron triggered correlated yields in Au+Au collisions at sqrt(sNN) = 200 GeV from STAR. The results are compared to Pythia calculations, and the implications for energy loss and jet fragmentation are discussed.