Inclusive Σ+ and Σ0 production in hadronic Z decays

Abstract We report on measurements of the inclusive production rate of Σ + and Σ 0 baryonsin hadronicZ decays collected with the L3 detector at LEP. The Σ + baryonsare detected through the decay Σ + →p π 0 , while the Σ 0 baryonsare detected via the decay mode Σ 0 → Λγ . The average numbers of Σ + and Σ 0 per hadronicZ decay are measured to be: N Σ + + N Σ + =0.114±0.011 stat±0.009 syst N Σ 0 + N Σ 0 =0.095±0.015 stat±0.013 syst . These rates are found to be higher than the predictions from Monte Carlo hadronizationmodels and analytical parameterizations of strange baryonproduction.