K-/K+ and p̄/p ratios measured in 158 A·GeV Pb + Pb collisions are shown as a function of centrality and transverse momentum (Pt). Little significant centrality dependence in neither K-/K+ nor p̄/p ratios are observed and they are almost constant as a function of Pt. The chemical freeze-out temperature Tch and the chemical potentials for both light and strange quarks (μq,μs) are extracted by comparing the present data with simple model predictions. The μq,μs and Tch from the NA44 are compared with those obtained from similar analysis of SPS S + A and AGS Si + A data. The chemical freeze-out temperature Tch in GERN energy is higher than thermal freeze-out temperature Tfo which is extracted from transverse momentum distribution of charged hadrons. In AGS energy Tch is close to Tfo.
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