MULTIPLICITIES AND HADRONIC FINAL STATES IN e+e'-INTERACTIONS AT THE Z-RESONANCE

摘要

Multiplicities and inclusive spectra of charged and neutral hadrons have been measured in the decay of the Z produced in e+e~-interactions. Charged par-ticles are identified by their characteristic ionization energy-loss or Cherenkov-radii and neutral or short-lived ones by their reconstructed invariant mass. Final state particles are dominated by pions especially at low momenta with decreas-ing tendency to higher momenta, where kaons represent a significant fraction. The high statistics of LEP experiments also permits to determine the multiplic-ities of hadrons with low production cross section, such as B°, rf, S° and Or. A comparison of the inclusive spectra and rates with predictions of JETSET and HERWIG Monte Carlo models is presented. The multiplicities are also separate-ly determined for quark and gluon jets. There is a significant excess of hadrons in gluon compared to quark initiated jets. However, the difference is much more pronounced at the subjet level.