STRANGENESS PRODUCTION IN NUCLEAR-INTERACTIONS AT 200 A GEV AND THE NUMBER OF NUCLEON-NUCLEON COLLISIONS

Data on mean numbers of Lambda, <(Lambda)over bar>, K's and on the tot al number [ s (s) over bar ] of pairs of strange valence quarks in fin al state hadrons in hadronic and nuclear collisions at CERN-SPS energi es are studied as a function of the mean number [ n(coll) ] of nucleon -nucleon collisions. Results give indications of an almost linear depe ndence over most of the region of [ n(coll) ]. This in turn points out to strangeness being produced mostly in the central rapidity region o f nucleon-nucleon collisions by a mechanism similar to a hard or semi- hard process. The available data are extrapolated to Pb+Pb interaction s by two simple models, leading to [ s (s) over bar ](Pb+Pb) approxima te to 300 +/- 30 Observations exceeding these values of [ s (s) over b ar ](Pb+Pb) would give evidence of the onset of a new dynamical regime in Pb+Pb interactions.