Critical opacity: a possible explanation of the fast thermalization times seen in BNL RHIC experiments.
The Nambu-Jona-Lasinio Lagrangian offers an explication of the seemingly contradictory observations that (a) the energy loss in the entrance channel of heavy ion reactions is not sufficient to thermalize the system and that (b) the observed hadron cross sections are in almost perfect agreement with hydrodynamical calculations. According to this scenario, a critical opacity develops close to the chiral phase transition which equilibrates and hadronizes the expanding system very effectively. It creates as well radial flow and, if the system is not isotropic, finite upsilon2 values.
Gastineau
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SUBATECH, Laboratoire de Physique Subatomique et des Technologies Associées, University of Nantes-IN2P3/CNRS-Ecole des Mines de Nantes, 4 rue Alfred Kastler, F-44072 Nantes, CEDEX 03, France.
Blanquier
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Aichelin
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