ar X iv : n uc l - ex / 9 81 00 05 v 1 7 O ct 1 99 8 Ξ and Ξ Production in 158 GeV / Nucleon Pb + Pb Collisions ( The NA
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چکیده
We report measurements of Ξ and Ξ + hyperon absolute yields as a function of rapidity in 158 GeV/c Pb+Pb collisions. At midrapidity, dN dy = 2.29± 0.12 for Ξ, and 0.52 ± 0.05 for Ξ+, leading to the ratio of Ξ+/Ξ−=0.23±0.03. Inverse slope parameters fitted to the measured transverse mass spectra are of the order of T ≈ 300 MeV near mid-rapidity. The estimated total yield of Ξ particles in Pb+Pb central interactions amounts to 7.4±1.0 per collision. Comparison to Ξ production in properly scaled p+p reactions at the same energy reveals a dramatic enhancement (about one order of magnitude) of Ξ production in Pb+Pb central collisions over elementary hadron interactions. Submitted to Physics Letters B
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