A MEASUREMENT OF THE PRODUCTION OF D-ASTERISK(+/-) MESONS ON THE Z(0) RESONANCE

We have studied the production of D*(+/-) mesons in a sample of 1,25 million multihadronic decays of the Z(0), in which 1969 candidates have been identified. We have determined the total multiplicity of charged D* mesons in multihadronic Z(0) decays to be (n) over bar)(Z0-->D*+/-X) = 0.183 +/- 0.009(stat) +/- 0.007(sys) +/-0.008(ext). The last error is due to branching ratios external to this analysis. Decays of c-quarks are separated from those of b-quarks by a combination of bottom tagging methods using leptons, jet shape variables, and lifetime information. From this we find Gamma(Z(0) --> <c(c)over bar>)/Gamma(Z(0) --> hadrons) = 0.142 +/- 0.008(stat) +/- 0.009(sys) +/- 0.011(ext). We measure the mean scaled energy of D*(+/-) mesons in primary charm events to be [x(c-->D*+/-)] = 0.515(-0.005)(+0.008)(stat) +/- 0.010(sys). Studying D* production at very low x(D)* we find indications for <c(c)over bar> production from gluon splitting and measure the mean multiplicity of this process in multihadronic Z(0) decays to be (n) over bar(g--><c(c)over bar>) = 0.044 +/- 0.014(stat) +/- 0.015(sys), assuming the Standard Model prediction for Gamma(<c(c)over bar>)/Gamma(had). By comparing our observed D* mean scaled energy with measurements at lower energies we find evidence for scaling violations.