Charmed and Strange.baryon Production in 29 Gev Electron Positron Annihilation*

Baryon production is one of the least understood areas of hadron production in electron positron collisions. Early models of hadronization predicted that very few baryons should be produced. However, experiments have shown a very substantial rate of baryon production, and many different models have been proposed to explain this. One way to test these models, and to further probe the hadronization process is to measure the production rates of different types of baryons. This dtirtation presents measurements of the production rates of baryons with different strangeness and spin. The analyses presented here use data taken with the Mark II detector at the PEP storage ring, operating at a center of mass energy of 29 GeV. The Hproduction rate is measured to be 0.017 f 0.004 f 0.004 per hadronic event, Rproduction is measured to be 0.014 f 0.006 f 0.004 per hadronic event, and B*O production is less than 0.006 per hadronic event at a 90% confidence level. These measurements place strong constraints on models of baryon production. In particular, the unexpectedly high rate of s2production is difficult to explain in any diquark based model. Semileptonic A$ decays have also been observed, with a(e+e--) A,X) t &(A, + eAX) = 0.0031 f 0.0012 f 0.0010 per hadronic event, and a(e+e--+ A,X) * Br(A, + PAX) = 0.0024 & 0.0024 f 0.0007 per hadronic event. Because neither the branching ratios nor the production rate are well known, it is difficult to interpret these results. However, they do indicate that the branching ratio for A$+ Alv may be higher than previous experimental measurements.