Dihadron and gamma-hadron correlations from jet-induced medium excitation in high-energy heavy-ion collisions

TL;DR

This paper investigates how jet-induced medium excitation, including Mach cones and other effects, influences dihadron and gamma-hadron correlations in high-energy heavy-ion collisions, revealing the origins of double-peaked azimuthal correlations.

Contribution

It distinguishes the effects of harmonic flow, hot spots, and dijets on dihadron correlations and compares them with gamma-hadron correlations to clarify jet-medium interactions.

Findings

Dihadron correlations can be double-peaked due to multiple effects.

Gamma-hadron correlations show similar features but lack flow and hot spot contributions.

Comparison helps identify jet-induced medium excitation mechanisms.

Abstract

Jet propagation is shown to produce Mach-cone-like medium excitation inside a quark-gluon plasma. However, only deflection of such medium excitation and jet shower partons by radial flow leads to double-peaked dihadron correlation in high-energy heavy-ion collisions. Dihadron correlations from harmonic flow, hot spots and dijets are studied separately within the AMPT Monte Carlo model and all lead to double-peaked dihadron azimuthal correlation. The $\gamma$-hadron correlation has similar double-peak feature but is free of the contributions from harmonic flow and hot spots. Dihadron and $\gamma$-hadron correlations are compared to shed light on jet-induced medium excitation and hot spots in an expanding medium.