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 ch amber 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. Inclus ive features such as LAMBDA, K(s)0 and SIGMA0 (the first time for the last particle) rates are presented, together with momentum and rapidit y distributions. Semi-inclusive double-strangeness final states LAMBDA KX, SIGMAKX and KKXBAR are also presented. The observation of almost a ll strange channels allowed one to deduce the effective total strangen ess content which turned out to be (6.2+/-0.9)%. The K/pi ratios, toge ther with the mean multiplicities of protons, pi+/- and pi0 mesons ass ociated or not to strangeness production are also given. The results h ave been compared with a modified version of the standard intranuclear cascade model obtaining, within the model uncertainties, a good agree ment under the assumption that the produced hyperons have no further n uclear interaction (no elastic scattering and no sticking).