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تسجيل مستخدم جديدStatistical description with anisotropic momentum distributions for hadron production in nucleus-nucleus collisions
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The various experimental data at AGS, SPS and RHIC energies on hadron particle yields for central heavy ion collisions are investigated by employing a generalized statistical density operator, that allows for a well-defined anisotropic local momentum distribution for each particle species, specified by a common streaming velocity parameter. The individual particle ratios are rather insensitive to a change in this new intensive parameter. This leads to the conclusion that the reproduction of particle ratios by a statistical treatment does not imply the existence of a fully isotropic local momentum distribution at hadrochemical freeze-out, i.e. a state of almost complete thermal equilibrium.
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High-energy nucleus-nucleus collisions are studied in multi-chain model with successive collision. Analytic forms for single-particle distribution are derived.
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