System-size scan of dihadron azimuthal correlations in ultra-relativistic heavy ion collisions

TL;DR

This study uses a multi-phase transport model to analyze how dihadron azimuthal correlations depend on system size in ultra-relativistic heavy ion collisions, revealing size-dependent structures linked to partonic phases.

Contribution

It demonstrates the system-size dependence of correlation structures and identifies conditions for double-peak formation related to the partonic phase in heavy ion collisions.

Findings

Correlation functions depend on participant path length.

Double-peak structures form only in large systems with partonic phase.

Contrast with hadron gas results hints at deconfinement onset.

Abstract

System-size dependence of dihadron azimuthal correlations in ultra-relativistic heavy ion collision is simulated by a multi-phase transport model. The structure of correlation functions and yields of associated particles show clear participant path-length dependences in collision systems with a partonic phase. The splitting parameter and root-mean-square width of away-side correlation functions increase with collision system size from $^{14}$N+$^{14}$N to $^{197}$Au+$^{197}$Au collisions. The double-peak structure of away-side correlation functions can only be formed in sufficient "large" collision systems under partonic phase. The contrast between the results with partonic phase and with hadron gas could suggest some hints to study onset of deconfinment.