Inclusive Σ<SUP>+</SUP> and Σ<SUP>0</SUP> production in hadronic Z decays

Abstract

We report on measurements of the inclusive production rate of Σ+ and Σ0 baryons in hadronic Z decays collected with the L3 detector at LEP. The Σ+ baryons are detected through the decay Σ+→pπ0, while the Σ0 baryons are detected via the decay mode Σ0→Λγ. The average numbers of Σ+ and Σ0 per hadronic Z decay are measured to be:

<math><mtext>N</mtext><msub><mi></mi><mn><mtext>Σ</mtext><msup><mi></mi><mn>+</mn></msup></mn></msub><mtext>+</mtext><mtext>N</mtext><msub><mi></mi><mn><mtext>Σ</mtext><mtext>̄</mtext><msup><mi></mi><mn>+</mn></msup></mn></msub><mtext>=0.114±0.011</mtext><msub><mi></mi><mn><mtext>stat</mtext></mn></msub><mtext>±0.009</mtext><msub><mi></mi><mn><mtext>syst</mtext></mn></msub></math>

<math><mtext>N</mtext><msub><mi></mi><mn><mtext>Σ</mtext><msup><mi></mi><mn>0</mn></msup></mn></msub><mtext>+</mtext><mtext>N</mtext><msub><mi></mi><mn><mtext>Σ</mtext><mtext>̄</mtext><msup><mi></mi><mn>0</mn></msup></mn></msub><mtext>=0.095±0.015</mtext><msub><mi></mi><mn><mtext>stat</mtext></mn></msub><mtext>±0.013</mtext><msub><mi></mi><mn><mtext>syst</mtext></mn></msub><mspace sp="0.2" width="2px" linebreak="nobreak" is="true"></mspace><mtext>.</mtext></math>

These rates are found to be higher than the predictions from Monte Carlo hadronization models and analytical parameterizations of strange baryon production.