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

摘要

Data on mean numbers of Λ, Λ-bar, K's and on the total number < s(s-bar) > 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 < n_(coll) > of nucleon-nucleon collisions. Results give indications of an almost linear dependence over most of the region of < n_(cott) >. 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 < s(s-bar) > Pb+Pb ≈ 300 ± 30. Observations exceeding these values of < s(s-bar) > Pb+Pb would give evidence of the onset of a new dynamical regime in Pb+Pb interactions.