# Event-plane dependent away-side jet-like correlation shape in Au+Au collisions at $\sqrt{s_{NN}}=200$ GeV from STAR

## TL;DR

This study investigates how the shape of away-side jet-like correlations in Au+Au collisions varies with the event-plane orientation, revealing jet-medium interactions through a novel background subtraction and unfolding method.

## Contribution

Introduces a data-driven background subtraction method using eta-separated regions and unfolding to study event-plane dependent jet correlations in heavy-ion collisions.

## Key findings

- Jet-like correlation width increases with path length.
- Effective background subtraction reduces flow effects.
- Evidence of jet-medium interactions from correlation broadening.

## Abstract

We employ a data-driven method to subtract the flow background of all harmonics by calculating the difference of the two-particle correlations between the close-region and far-region, determined depending on the pseudo-rapidity ($\eta$) distance from the region where an enhanced recoil transverse momentum ($P_x$) from a high-$p_T$ trigger particle is selected. We analyze the correlation shape as a function of the trigger particle azimuthal angle relative to the event-plane (EP) reconstructed from the beam-beam counters (BBCs) which are displaced by several units in $\eta$ from the mid-rapidity region. The large $\eta$ gap can effectively eliminate the auto-correlation between trigger particles and EP. We correct for the relatively large resolution effect from the BBC EP determination via an unfolding procedure. The width of unfolded away-side jet-like correlation increases with longer path-length, which is an indication of jet-medium interactions.