Triangular flow in event-by-event ideal hydrodynamics in Au+Au collisions at $\sqrt{s_{\rm NN}}=200A$ GeV

TL;DR

This paper presents the first event-by-event ideal hydrodynamics calculation of triangular flow $v_3$ in Au+Au collisions at 200A GeV, showing it has weak centrality dependence and similar magnitude to elliptic flow.

Contribution

It introduces a novel event-by-event (3+1)d hydrodynamics approach to compute triangular flow in heavy-ion collisions at RHIC energies.

Findings

Triangular flow $v_3$ exhibits weak centrality dependence.

$v_3$ is roughly equal to elliptic flow $v_2$ in most central collisions.

The model reproduces key features of triangular flow observed in experiments.

Abstract

The first calculation of triangular flow $v_3$ in Au+Au collisions at $\sqrt{s_{\rm NN}}=200A$ GeV from an event-by-event (3+1)-d transport+hydrodynamics hybrid approach is presented. As a response to the initial triangularity $\epsilon_3$ of the collision zone, $v_3$ is computed in a similar way to the standard event-plane analysis for elliptic flow $v_2$. It is found that the triangular flow exhibits weak centrality dependence and is roughly equal to elliptic flow in most central collisions. We also explore the transverse momentum and rapidity dependence of $v_2$ and $v_3$ for charged particles as well as identified particles. We conclude that an event-by-event treatment of the ideal hydrodynamic evolution starting with realistic initial conditions generates the main features expected for triangular flow.