Untersuchung vom Myonen aus semileptonischen Zo- Zerfaellen - Bestimmung der partiellen b-Quark-Breite und der Fragmentierungsfunktion

Hadronic final states in e+e- annihilation at y's ~ mz, collected 1990/91 by the DELPHI detector at LEP, have been analysed. Results about the fragmentation functions of b-quarks, the bb partial width rbb and the semileptonic branching ration BsL(b-+μ) have been obtained. The tagging of b-quark events has been performed using the semileptonic decay channel b-+ X+μ. To measure the product of the Z 0 decay width to bb and the branching fraction of the the b-quark to muons together with the mean scaled energy of the B-hadron, the observed two-dimensional PT versus p distribution of muons has been fitted. The experimental results obtained from approximately 16 000 analysed events are:...The quoted errors combine statistical and systematical uncertainties.