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Chemical nonequilibrium and deconfinement in 200{ital A} GeV sulphur induced reactions

Journal Article · · Physical Review, C
;  [1]
  1. Department of Physics, University of Arizona, Tucson, Arizona 85721 (United States)
We interpret hadronic particle abundances produced in S-Au/W/Pb 200A 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 nonequilibrium a highly significant fit to experimental particle abundance data emerges, which supports the possibility of strangeness distillation. We find under different strategies stable values for freeze-out temperature T{sub f}=143{plus_minus}3 MeV, baryochemical potential {mu}{sub B}=173{plus_minus}6 MeV, ratio of strangeness ({gamma}{sub s}) and light quark ({gamma}{sub q}) phase space occupancies {gamma}{sub s}/{gamma}{sub q}=0.60{plus_minus}0.02, and {gamma}{sub q}=1.22{plus_minus}0.05 without accounting for collective expansion (radial flow). When introducing flow effects which allow a consistent description of the transverse mass particle spectra, yielding {vert_bar}{rvec v}{sub c}{vert_bar}=0.49{plus_minus}0.01 c, we find {gamma}{sub s}/{gamma}{sub q}=0.69{plus_minus}0.03, {gamma}{sub q}=1.41{plus_minus}0.08. The strange quark fugacity is fitted at {lambda}{sub s}=1.00{plus_minus}0.02 suggesting chemical freeze-out directly from the deconfined phase. {copyright} {ital 1999} {ital The American Physical Society}
OSTI ID:
304282
Journal Information:
Physical Review, C, Journal Name: Physical Review, C Journal Issue: 2 Vol. 59; ISSN 0556-2813; ISSN PRVCAN
Country of Publication:
United States
Language:
English