Measurement of the production rates of charged hadrons ine ⁺ e ⁻-annihilation at theZ ⁰

Abstract

The inclusive production rates of π^±,K ^± andp $\bar p$ inZ ⁰ decays have been measured with the OPAL detector at LEP. Using the energy loss measurement in the jet chamber, the momentum range up to the beam energy (45.6 GeV/c) has been covered. Differential cross sections and total particle yields are given. Comparisons of the inclusive momentum spectra and the total rates with predictions of the JETSET and the HERWIG Monte Carlo model are presented. The total single rates are found to be 17.05±0.43 π^±, 2.42±0.13K ^± and 0.92±0.11p $\bar p$ per hadronic event. Predictions of JETSET for cross sections and total rates agree very well for π^±; however, for momenta greater than 4 GeV/c,K ^± rates are underestimated and$\bar p$ rates are overestimated. Combined with data of other particle species there is evidence that the peak positions in the ξ=ln(1/x _p ) distributions show a different mass dependence for mesons and baryons. However, both JETSET and HERWIG Monte Carlo predictions agree with the observed data.