Production of multi-strange hyperons and strange resonances in the NA49 experiment

The NA49 large-acceptance hadron spectrometer has measured strange and multi-strange hadrons from Pb+Pb and p+p collisions at the CERN SPS. Preliminary results for the transverse mass and rapidity distributions for X and Xi^+ from central Pb+Pb collisions at 158 GeV c^-1 nudeon are presented. Fully integrated yields per event of 4.42+or-0.31 and 0.74+0.04 are found for Xi^- and Xi^+, respectively, leading to a 4 pi Xi^+ Xi^- ratio of 0.17+or-0.02. The ratio Xi^+ Xi^- at mid-rapidity is found to be 0.22+or-0.04, agreeing with previously published values. In addition, preliminary data on the Lambda (1520) and phi (1020) resonances are presented. The Lambda (1520) multiplicity for p+p collisions is found to be 0.012+or-0.003. No signal is observed for Pb+Pb collisions and a production upper limit of 1.36 Lambda (1520) per event indicates an apparent suppression when comparing with scaled p+p data. Integrated phi (1020) yields per event are found to be 7.6+or-1.1 for Pb+Pb and 0.012+or-0.0015 for p+p collisions. No significant shift or broadening of the phi (1020) invariant mass distribution is observed in central Pb+or-Pb collisions.