STRANGE-PARTICLE PRODUCTION IN (P)OVER-BAR-XE ANNIHILATION AT REST AND AT 0.4-0.9 GEV/C

From a sample of 20 000 pXeBAR annihilations obtained in the bubble chamber DIANA a search has been made for strange-particle production at rest and in flight (0.4-0.9 GeV/c) taking advantage also of the unique capability of the chamber to detect neutral (photon) channels. Inclusive features such as LAMBDA, K(s)0 and SIGMA0 (the first time for the last particle) rates are presented, together with momentum and rapidity distributions. Semi-inclusive double-strangeness final states LAMBDAKX, SIGMAKX and KKXBAR are also presented. The observation of almost all strange channels allowed one to deduce the effective total strangeness content which turned out to be (6.2+/-0.9)%. The K/pi ratios, together with the mean multiplicities of protons, pi+/- and pi0 mesons associated or not to strangeness production are also given. The results have been compared with a modified version of the standard intranuclear cascade model obtaining, within the model uncertainties, a good agreement under the assumption that the produced hyperons have no further nuclear interaction (no elastic scattering and no sticking).