Anisotropic flow of charged and identified hadrons at FAIR energies and its dependence on the nuclear equation of state

TL;DR

This study investigates how the anisotropic flow of charged and identified hadrons in mid-central Au+Au collisions at FAIR energies depends on the nuclear equation of state, using different simulation models and hydrodynamic scenarios.

Contribution

It introduces a comparative analysis of flow parameters using UrQMD in pure and hybrid modes with different equations of state, highlighting the EoS sensitivity of flow observables.

Findings

Flow parameters are sensitive to the onset of hydrodynamic expansion.

Results vary with different equations of state, indicating potential to distinguish hadronic and partonic scenarios.

Predictions provided for upcoming experiments at FAIR and NICA.

Abstract

In this article, we examine the equation of state (EoS) dependence of the anisotropic flow parameters ($v_{1}$, $v_{2}$ and $v_{4}$) of charged and identified hadrons, as a function of transverse momentum ($p_{\rm T}$), rapidity ($y_{c.m.}$) and the incident beam energy ($\rm E_{\rm Lab}$) in mid-central Au + Au collisions in the energy range $\rm E_{\rm Lab} = 6 -25$ A GeV. Simulations are carried out by employing different variants of the Ultra-relativistic Quantum Molecular Dynamics (UrQMD) model, namely the pure transport (cascade) mode and the hybrid mode. In the hybrid mode, transport calculations are coupled with the ideal hydrodynamical evolution. Within the hydrodynamic scenario, two different equations of state (EoS) viz. Hadron gas and Chiral + deconfinement EoS have been employed separately to possibly mimic the hadronic and partonic scenarios, respectively. It is observed that the flow parameters are sensitive to the onset of hydrodynamic expansion of the fireball in comparison to the pure transport approach. The results would be useful as predictions for the upcoming low energy experiments at Facility for Antiproton and Ion Research (FAIR) and Nuclotron-based Ion Collider fAcility (NICA).