Initial fluctuations and dihadron and $\gamma$-hadron correlations in high-energy heavy ion collisions

TL;DR

This paper investigates the origins of azimuthal dihadron and gamma-hadron correlations in high-energy heavy-ion collisions, focusing on initial fluctuations, jet-medium interactions, and hydrodynamic evolution, using the AMPT model.

Contribution

It distinguishes the effects of initial fluctuations and jet-medium interactions on correlation signals by removing harmonic flow background in simulations.

Findings

Initial fluctuations significantly influence dihadron correlations.

Gamma-hadron correlations primarily reflect jet-medium interactions.

Net correlations vary with different initial conditions.

Abstract

Jets, jet-medium interaction and hydrodynamic evolution of fluctuations in initial parton density all lead to the final anisotropic dihadron azimuthal correlations in high-energy heavy-ion collisions. We remove the harmonic flow background and study the net correlations from different sources with different initial conditions within the AMPT model. We also study $\gamma$-hadron correlations which are only influenced by jet-medium interactions.