Reaction Plane Dependent Away-side Modification and Near-side Ridge in Au+Au Collisions

TL;DR

This study investigates how di-hadron correlations in Au+Au collisions depend on the trigger particle's azimuthal angle relative to the event plane, revealing modifications in the correlation structures.

Contribution

It provides the first detailed analysis of reaction plane dependence of di-hadron correlations, distinguishing between jet and ridge components in heavy-ion collisions.

Findings

Away-side correlation changes from single- to double-peak with increasing $\phi_s$.

Near-side ridge decreases with $\phi_s$, while jet component remains stable.

Correlation structures vary significantly with the trigger particle's azimuthal angle.

Abstract

STAR preliminary results of di-hadron correlations versus $\phi_{s}$, the trigger particle azimuthal angle relative to the constructed event plane are reported for mid-central Au+Au collisions and compared to central Au+Au as well as minimum bias d+Au collisions. The correlations are observed to vary with $\phi_{s}$ on both the near and away side of the trigger particle. The away-side correlation evolves from single- to double-peak with increasing $\phi_{s}$. The near-side correlation is separated into 'jet' and 'ridge': the ridge is found to decrease with $\phi_{s}$ while the jet remains relatively constant.