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arXiv · 0812.0375

Effects of a phase transition on HBT correlations in an integrated Boltzmann+Hydrodynamics approach

Qingfeng Li·Jan Steinheimer·Hannah Petersen·Marcus Bleicher·Horst Stoecker
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Abstract

A systematic study of HBT radii of pions, produced in heavy ion collisions in the intermediate energy regime (SPS), from an integrated (3+1)d Boltzmann+hydrodynamics approach is presented. The calculations in this hybrid approach, incorporating an hydrodynamic stage into the Ultra-relativistic Quantum Molecular Dynamics transport model, allow for a comparison of different equations of state retaining the same initial conditions and final freeze-out. The results are also compared to the pure cascade transport model calculations in the context of the available data. Furthermore, the effect of different treatments of the hydrodynamic freeze-out procedure on the HBT radii are investigated. It is found that the HBT radii are essentially insensitive to the details of the freeze-out prescription as long as the final hadronic interactions in the cascade are taken into account. The HBT radii $R_L$ and $R_O$ and the $R_O/R_S$ ratio are sensitive to the EoS that is employed during the hydrodynamic evolution. We conclude that the increased lifetime in case of a phase transition to a QGP (via a Bag Model equation of state) is not supported by the available data.

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Qingfeng Li, Jan Steinheimer, Hannah Petersen, Marcus Bleicher, Horst Stoecker. 2009-03-20. Effects of a phase transition on HBT correlations in an integrated Boltzmann+Hydrodynamics approach. https://doi.org/10.1016/j.physletb.2009.03.012

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