Semi-inclusive Lambda and K-S production in p-Au collisions at 17.5 GeV/c

The first detailed measurements of the centrality dependence of strangeness production In p-A collisions are presented. Lambda and K-S dn/dy distribut ions from 17.5 GeV/c p-Au collisions are shown as a function of "grey" trac k multiplicity and the estimated number of collisions, nu, made by the prot on. The nu dependence of the Lambda yield deviates from a scaling of p-p da ta by the number of participants, increasing faster than this scaling for n u less than or equal to 5 and saturating for larger nu. A slower growth in K-S multiplicity with nu is observed, consistent with a weaker nu dependenc e of K (K) over bar production than YK production.