Determination of the momentum distributions of charged hadrons from Z0 decays by means of dE/dx measurements in the jet chamber of the OPAL detector

Inclusive measurements of momentum distributions of π±, K± and panti p are presented from an analysis of approximately 145000 hadronic decays of the Z0 collected in 1990 with the OPAL detector at LEP. The rates of the charged hadrons are determined by simultaneous measurement of the momentum and the energy loss dE/dχ for each charged track. Fits to the dE/dχ distributions in several momentum bins are performed using 4 gaussian functions. From the entries under each of these 4 gaussians the rates for the most numerous charged particle types (e±, π±+μ±, K± and panti p) are calculated and corrected for efficiency and other detector-dependent effects. With these rates the momentum distributions and the fragmentation functions for π±, K± and panti p are derived and compared to Monte Carlo predictions. Good agreement is found with the JETSET model with the exception of low momentum protons. (orig.)