Speaker
Description
A novel hybrid approach coupling the hadronic transport approach SMASH to the 3+1D viscous hydrodynamics code vHLLE is introduced. The SMASH-vHLLE-hybrid is suitable to describe heavy-ion collisions ranging from $\sqrt{s}_\mathrm{NN}$ = 4.3 GeV - 5.02 TeV and is publicly available on Github. This talk focuses on collisions towards the high baryon-density regime of the QCD phase diagram, where the first order phase transition and critical end point are expected. Experimentally, this region of the phase diagram is studied within the NA61/SHINE experiment at CERN, the recently conducted BESII program at RHIC and the future FAIR and NICA facilities. After a thorough validation, the SMASH-vHLLE-hybrid is applied to study particle production and collective flow over a large range of beam energies. It is demonstrated that hadron dN/dy and m$_\mathrm{T}$ spectra are in good agreement with experimental measurements. In particular, it is found that the SMASH-vHLLE-hybrid is capable of properly capturing the baryon stopping dynamics in collisions at finite baryon densities. The transition from a Gaussian net baryon distribution to a double-hump structure as a function of rapidity can be reproduced. The agreement with experimental data for multiplicity, mean p$_\mathrm{T}$ excitation functions and flow is significantly improved as compared to a pure hadronic transport evolution.
This work constitutes a first step in systematically studying heavy-ion collisions at finite baryon densities. Next, the SMASH-vHLLE-hybrid can be applied with different equations of state -with and without first order phase transition- to study the implications for final state observables, particularly focusing on those sensitive to a phase transition.
References:
- A. Schäfer, I. Karpenko, H. Elfner: arXiv: 2109.08578
- A. Schäfer, I. Karpenko, X.-Y. Wu, J. Hammelmann, H. Elfner: "Particle production in a hybrid approach for a beam energy scan of Au+Au/Pb+Pb collisions between $\sqrt{s}_\mathrm{NN}$ = 4.3 GeV and $\sqrt{s}_\mathrm{NN}$ = 200.0 GeV", in preparation
- Github: https://github.com/smash-transport/smash-vhlle-hybrid
