Strangeness production in nuclear interactions at 200 A GeV and the number of nucleon-nucleon collisions

Data on mean numbers of A, Ā, K’s and on the total number \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document} $$ < s\bar s > $$ \end{document} of pairs of strange valence quarks in final state hadrons in hadronic and nuclear collisions at CERN-SPS energies are studied as a function of the mean number < ncoll > of nucleon-nucleon collisions. Results give indications of an almost linear dependence over most of the region of < ncoll >. This in turn points out to strangeness being produced mostly in the central rapidity region of nucleon-nucleon collisions by a mechanism similar to a hard or semi-hard process. The available data are extrapolated to Pb+Pb interactions by two simple models, leading to \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document} $$ < s\bar s > _{Pb + Pb} \approx 300 \pm 30$$ \end{document}. Observations exceeding these values of \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document} $$ < s\bar s > _{Pb + Pb} $$ \end{document} would give evidence of the onset of a new dynamical regime in Pb+Pb interactions.