Using a sample of about 1.46 million hadronic Z decays collected between 1991 and 1993 with the ALEPH detector at LEP, the energy distribution of the B-0 and B+/- mesons produced at the Z resonance is measured by reconstructing semileptonic decays B -> l nu(l)D(X) or B -> l nu(l)D*(+)(X). The charmed mesons are reconstructed through the decay modes D-0 -> K(-)pi(+), D-0 -> K(-)pi(+)pi(-)pi(+),D+ -> K(-)pi(+)pi(+), and D*(+) -> D-0 pi(+). The neutrino energy is estimated from the missing energy in the lepton hemisphere. Accounting for B* and B** production, the shape of the scaled energy distribution x(E)((b)) for mesons containing a b quark is compared to the predictions of different fragmentation models. The mean value of x(E)((b)) is found to be <x(E)((b))> = 0.715 +/- 0.007(stat) +/- 0.013(syst).
Measurement of the Effective b quark Fragmentation Function At the Z resonance
G. BATIGNANI;CIOCCI, MARIA AGNESE;FERRANTE, ISIDORO;MESSINEO, ALBERTO MARIA;TONELLI, GUIDO EMILIO;G. TRIGGIANI;
1995-01-01
Abstract
Using a sample of about 1.46 million hadronic Z decays collected between 1991 and 1993 with the ALEPH detector at LEP, the energy distribution of the B-0 and B+/- mesons produced at the Z resonance is measured by reconstructing semileptonic decays B -> l nu(l)D(X) or B -> l nu(l)D*(+)(X). The charmed mesons are reconstructed through the decay modes D-0 -> K(-)pi(+), D-0 -> K(-)pi(+)pi(-)pi(+),D+ -> K(-)pi(+)pi(+), and D*(+) -> D-0 pi(+). The neutrino energy is estimated from the missing energy in the lepton hemisphere. Accounting for B* and B** production, the shape of the scaled energy distribution x(E)((b)) for mesons containing a b quark is compared to the predictions of different fragmentation models. The mean value of x(E)((b)) is found to beI documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.