language: en

Strangeness production in hadronic models and recombination models

Gunnar Gräf 1 , Elvira Santini 1 , Hannah Petersen 1,2 , Jan Steinheimer 1 , Michael Mitrovski 3 , Marcus Bleicher 3
1 Institut für Theoretische Physik, Goethe Universität Frankfurt,
Germany
2 Department of Physics, Duke University,
Durham, NC 27708, United States
3 Frankfurt Institute for Advanced Studies (FIAS),
Ruth-Moufang-Str. 1, 60438 Frankfurt, Germany
E-mail: bleicher@th.physik.uni-frankfurt.de

Abstract. We present recent results on the production, spectra and elliptic flow of strange particles in dynamic simulations employing hadronic degrees of freedom and from recombination models. The main focus will be on the Ultra-relativistic Molecular Dynamics (UrQMD) Boltzmann approach to relativistic heavy ion collisions and a hybrid approach with intermediate hydrodynamic evolution based on UrQMD (available for download as UrQMD v3.3). Compared to the standard binary collision approach, an enhancement of the strange particle particle yields is found in the hybrid approach due to the assumption of local equilibration. The production origins of the φ-meson in the hybrid approach are studied in further detail. We also present results on the transverse momentum spectra of baryon to meson ratios of strange particles. Due to the approximate energy independent scaling of this ratio as a function of p T we argue, that a maximum in these spectra may not be a unique sign for quark coalescence but can be understood in terms of flow and fragmentation.

[Strangeness production in hadronic models and recombination models 2]

1. Introduction