Hydrodynamic modeling of deconfinement phase transition in heavy-ion collisions at NICA-FAIR energies

TL;DR

This study employs (3+1)D ideal hydrodynamics to model the evolution of strongly interacting matter in heavy-ion collisions at NICA-FAIR energies, highlighting the impact of deconfinement phase transition on observable flow patterns.

Contribution

It introduces a hydrodynamic model incorporating two equations of state to analyze phase transition effects in heavy-ion collisions at energies relevant to NICA and FAIR.

Findings

Deconfinement transition broadens proton rapidity distributions.

It increases elliptic flow and creates directed antiflow.

Effects are most significant around 10 AGeV energy.

Abstract

We use (3+1) dimensional ideal hydrodynamics to describe the space-time evolution of strongly interacting matter created in Au+Au and Pb+Pb collisions. The model is applied for the domain of bombarding energies 1-160 AGeV which includes future NICA and FAIR experiments. Two equations of state are used: the first one corresponding to resonance hadron gas and the second one including the deconfinement phase transition. The initial state is represented by two Lorentz-boosted nuclei. Dynamical trajectories of matter in the central box of the system are analyzed. They can be well represented by a fast shock-wave compression followed by a relatively slow isentropic expansion. The parameters of collective flows and hadronic spectra are calculated under assumption of the isochronous freeze-out. It is shown that the deconfinement phase transition leads to broadening of proton rapidity distributions, increase of elliptic flows and formation of the directed antiflow in the central rapidity region. These effects are most pronounced at bombarding energies around 10 AGeV, when the system spends the longest time in the mixed phase. From the comparison with three-fluid calculations we conclude that the transparency effects are not so important in central collisions at NICA-FAIR energies (below 30 AGeV).