Three-fluid Hydrodynamics-based Event Simulator Extended by UrQMD final State interactions (THESEUS) for FAIR-NICA-SPS-BES/RHIC energies

TL;DR

The paper introduces a new event generator combining three-fluid hydrodynamics with UrQMD final state interactions, improving simulation accuracy for heavy-ion collisions at FAIR-NICA-SPS-BES/RHIC energies.

Contribution

It extends the 3FH approach with a UrQMD afterburner, providing a more comprehensive simulation of heavy-ion collision dynamics and final state interactions.

Findings

Reproduces 3FH results with high accuracy.

Analyzes effects of UrQMD afterburner on observables.

Provides insights into directed flow and particle spectra.

Abstract

We present a new event generator based on the three-fluid hydrodynamics (3FH) approach, followed by a particlization at the hydrodynamic decoupling surface and a subsequent UrQMD afterburner stage based on the microscopic UrQMD transport model that accounts for hadronic final state interactions. First results for Au+Au collisions are presented. The following topics are addressed: the directed flow, transverse-mass spectra, as well as rapidity distributions of protons, pions and kaons for two model equations of state, one with a first-order phase transition, the other with a crossover transition. Preliminary results on the femtoscopy are also discussed. We analyze the accuracy of reproduction of the 3FH results by the new event generator and the effect of the subsequent UrQMD afterburner stage.