Production rate and decay lifetime measurements of B(s)0 mesons at LEP using D(s) and phi mesons

The study of the properties of inclusive production ofD s mesons and of events in which a ϕ and a muon are present in the same jet provides two independent measurements of the probability,f s w , for a heavy quark to hadronize into a strangeB orD meson. The data sample analysed corresponds to 243,000 hadronicZ 0 decays. The combined value of these measurements isf s w =0.19±0.06±0.08. From the flight distance distributions ofD s and of (ϕ-lepton) secondary vertices, with the lepton emitted at high transverse momentum relative to the jet axis, two values are obtained for theB s 0 meson lifetime. Combining these measurements with a previous result based on the study ofD s-μ events, theB s 0 meson lifetime is measured to be: 0.96±0.37 ps

Charged particle multiplicity distributions for fixed number of jets in Z0 hadronic decays

The multiplicity distributions of charged particles in full phase space and in restricted rapidity intervals for events with a fixed number of jets measured by the DELPHI detector are presented. The data are well reproduced by the Lund Parton Shower model and can also be well described by fitted negative binomial distributions. The properties of these distributions in terms of the clan model are discussed. In symmetric 3-jet events the candidate gluon jet is found not to be significantly different in average multiplicity than the mean of the other two jets, thus supporting previous results of the HRS and OPAL experiments. Similar results hold for events generated according to the LUND PS and to the HERWIG models, when the jets are defined by the JADE jet finding algorithm. The method seems to be insensitive for measuring the color charge ratio between gluons and quarks. © 1992 Springer-Verlag.0SCOPUS: ar.jinfo:eu-repo/semantics/publishe