Anisotropic flow decorrelation in heavy-ion collisions at RHIC-BES energies with 3D event-by-event viscous hydrodynamics

TL;DR

This paper investigates anisotropic flow decorrelation in heavy-ion collisions at RHIC-BES energies using 3D event-by-event viscous hydrodynamics with different initial state models, providing insights into the initial conditions' effects on flow observables.

Contribution

It introduces a novel 3D extension of initial state models for viscous hydrodynamics at RHIC-BES energies and compares their impact on flow decorrelation.

Findings

Reproduction of elliptic flow at two collision energies.

Comparison of initial state models shows differences in flow decorrelation.

Initial state features influence the magnitude of flow decorrelation.

Abstract

In the RHIC Beam Energy Scan program, gold nuclei are collided with different collision energies in the range from few to 62.4 GeV. The goals of the program are to explore the onset of QGP creation, locate the critical point of QCD and study dense baryon matter. We report on the first application of Monte Carlo Glauber (GLISSANDO2) and T$_{\rm R}$ENTo $p=0$ initial states extended to 3D for event-by-event viscous fluid dynamic (vHLLE) with hadronic cascade modelling of Au+Au collisions at $\sqrt{s_{_{\rm NN}}}=27$ and 62.4 GeV, which is the upper region of RHIC BES energies. The initial states are extended into both the longitudinal direction and for finite baryon density using simple ans\"atze. The full energy and baryon charge counting in the initial states is implemented. We show the reproduction of elliptic flow, at both collision energies and with both initial states. We compare it also to the results obtained with UrQMD initial state. Furthermore, we show the results for rapidity decorrelation of elliptic flow $r_2$ at $\sqrt{s_{_{\rm NN}}}=27$ and 200 GeV from the same setup of hydrodynamic calculations with the 3D Monte Carlo Glauber and UrQMD initial states. We discuss the features of the initial states responsible for the magnitude of the observed flow decorrelation.