Beam energy scan using a viscous hydro+cascade model

14th International Conference on Strangeness in Quark Matter

Karpenko, Iu A.^1,2 ; Bleicher, M.^1,3 ; Huovinen, P.^1 ; Petersen, H.^1

Frankfurt Institute for Advanced Studies, Ruth-Moufang-Straße 1, 60438 Frankfurt am Main, Germany^1

Bogolyubov Institute for Theoretical Physics, 14-b Metrolohichna str., 03680 Kiev, Ukraine^2

Institute for Theoretical Physics, Johann Wolfgang Goethe Universität, Max-von-Laue-Str. 1, 60438 Frankfurt am Main, Germany^3

关键词: Baryon density;    Charged hadrons;    Collision-energy dependence;    Equation of state;    Experimental program;    Initial conditions;    Pb-Pb collisions;    Rapidity distribution;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/509/1/012067/pdf
DOI  :  10.1088/1742-6596/509/1/012067

来源: IOP

【 摘 要 】

Following the experimental program at BNL RHIC, we perform a similar «energy scan» using 3+1D viscous hydrodynamics coupled to the UrQMD hadron cascade, and study the collision energy dependence of pion and kaon rapidity distributions and mT-spectra, as well as charged hadron elliptic flow. To this aim the equation of state for finite baryon density from a Chiral model coupled to the Polyakov loop is employed for hydrodynamic stage. 3D initial conditions from UrQMD are used to study gradual deviation from boost-invariant scaling flow. We find that the inclusion of shear viscosity in the hydrodynamic stage of evolution consistently improves the description of the data for Pb-Pb collisions at CERN SPS, as well as of the elliptic flow measurements for Au-Au collisions in the Beam Energy Scan (BES) program at BNL RHIC. The suggested value of shear viscosity is η/s ≥ 0.2 for 6.3... 39 GeV.