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arXiv · hep-ph/9806386

Chemical non-equilibrium and deconfinement in 200 A GeV Sulphur induced reactions

Jean Letessier·Johann Rafelski
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Abstract

We interpret hadronic particle abundances produced in S--Au/W/Pb 200 A GeV reactions in terms of the final state hadronic phase space model and determine by a data fit of the chemical hadron freeze-out parameters. Allowing for the flavor abundance non-equilibrium a highly significant fit to experimental particle abundance data emerges, which supports possibility of strangeness distillation. We find under different strategies stable values for freeze-out temperature T_f=143\pm3 MeV, baryochemical potential μ_B= 173\pm6 MeV, ratio of strangeness (γ_s) and light quark (γ_q) phase space occupancies γ_s/γ_q=0.60\pm0.02, and γ_q=1.22\pm0.05 without accounting for collective expansion (radial flow). When introducing flow effects which allow a consistent description of the transverse mass particle spectra, yielding |v_c|=0.49\pm0.01c, we find γ_s/γ_q=0.69\pm0.03, γ_q=1.41\pm0.08. The strange quark fugacity is fitted at λ_s=1.00\pm0.02 suggesting chemical freeze-out directly from the deconfined phase.

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Jean Letessier, Johann Rafelski. 1998-10-06. Chemical non-equilibrium and deconfinement in 200 A GeV Sulphur induced reactions. https://doi.org/10.1103/physrevc.59.947

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