Reaction plane correlated triangular flow in Au+Au collisions at $\sqrt{s_{NN}}=3$ GeV

TL;DR

This study measures triangular flow relative to the reaction plane in Au+Au collisions at 3 GeV, revealing a significant proton $v_3$ signal influenced by rapidity, transverse momentum, and collision centrality, with implications for nuclear stopping and geometry.

Contribution

It provides the first measurement of reaction plane correlated triangular flow at this energy, highlighting the role of mean field potentials and nuclear geometry in flow development.

Findings

Significant $v_3$ signal observed for protons.

$v_3$ increases with rapidity, transverse momentum, and peripheral collisions.

Model comparisons indicate the necessity of mean field potentials.

Abstract

We measure triangular flow relative to the reaction plane at 3 GeV center-of-mass energy in Au+Au collisions at the BNL Relativistic Heavy Ion Collider. A significant $v_3$ signal for protons is observed, which increases for higher rapidity, higher transverse momentum, and more peripheral collisions. The triangular flow is essentially rapidity-odd with a slope at mid-rapidity, $dv_3/dy|_{(y=0)}$, opposite in sign compared to the slope for directed flow. No significant $v_3$ signal is observed for charged pions and kaons. Comparisons with models suggest that a mean field potential is required to describe these results, and that the triangular shape of the participant nucleons is the result of stopping and nuclear geometry.