Hyperon production in quark and gluon fragmentation at 10 GeV center-of-mass energy

A measurement of the production rates of the Λ, Ξ-, Σ0, Σ±(1385), Ξ0(1530), Ω- and Λ(1520) hyperons in the reactions e+e-→qanti q and e+e-→Υ→ggg is presented. An enhancement for ground state baryons in Υ decays of about 2.5-3 compared to the continuum data is observed. This large enhancement cannot be accomplished by standard fragmentation models and might be taken as indication for a different fragmentation of quarks and gluons. The observation of the Λ(1520) demonstrates the production of excited states in fragmentation processes. From the measured rates it follows that strangeness and spin suppression in hyperon production factorize. The suppression of strangeness is of order 0.3 as observed for mesons. This is not expected in the usual diquark models which predict a very low rate for diquarks carrying spin and strangeness. The low rate of decuplet states originates from a strong spin suppression, which cannot be accomodated by simple phase space arguments. (orig.)