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arXiv · 1308.3594

Chemical Freeze-out of Strange Particles and Possible Root of Strangeness Suppression

K. A. Bugaev·D. R. Oliinychenko·J. Cleymans·A. I. Ivanytskyi·I. N. Mishustin·E. G. Nikonov·V. V. Sagun
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Abstract

Two approaches to treat the chemical freeze-out of strange particles in hadron resonance gas model are analyzed. The first one employs their non-equillibration via the usual γ_s factor and such a model describes the hadron multiplicities measured in nucleus-nucleus collisions at AGS, SPS and RHIC energies with χ^2/dof = 1.15. Surprisingly, at low energies we find not the strangeness suppression, but its enhancement. Also we suggest an alternative approach to treat the strange particle freeze-out separately, but with the full chemical equilibration. This approach is based on the conservation laws which allow us to connect the freeze-outs of strange and non-strange hadrons. Within the suggested approach the same set of hadron multiplicities can be described better than within the conventional approach with χ^2/dof = 1.06. Remarkably, the fully equilibrated approach describes the strange hyperons and antihyperons much better than the conventional one.

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K. A. Bugaev, D. R. Oliinychenko, J. Cleymans, A. I. Ivanytskyi, I. N. Mishustin, E. G. Nikonov, V. V. Sagun. 2013-08-16. Chemical Freeze-out of Strange Particles and Possible Root of Strangeness Suppression. https://doi.org/10.1209/0295-5075%2F104%2F22002

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