8 research outputs found
Measurement of the Charged Multiplicities in b, c and Light Quark Events from Z0 Decays
Average charged multiplicities have been measured separately in , and
light quark () events from decays measured in the SLD experiment.
Impact parameters of charged tracks were used to select enriched samples of
and light quark events, and reconstructed charmed mesons were used to select
quark events. We measured the charged multiplicities:
,
, from
which we derived the differences between the total average charged
multiplicities of or quark events and light quark events: and . We compared
these measurements with those at lower center-of-mass energies and with
perturbative QCD predictions. These combined results are in agreement with the
QCD expectations and disfavor the hypothesis of flavor-independent
fragmentation.Comment: 19 pages LaTex, 4 EPS figures, to appear in Physics Letters
Erratum: Structure analysis of two Toxoplasma gondii and Neospora caninum satellite DNA families and evolution of their common monomeric sequence (Journal of Molecular Evolution) (2004) 58 (557-567))
Fil:Clemente, M. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.Fil:Lia, V.V. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.Fil:Matrajt, M. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.Fil:Angel, S.O. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina
First measurement of the double inclusive B / anti-B hadron energy distribution in e+ e- annihilations, and of angle dependent moments of the B and anti-B energies
We have made the first measurement of the double-inclusive B/Bbar energy
distribution in e+e- annihilations, using a sample of 400,000 hadronic Z0 decay
events recorded in the SLD experiment at SLAC between 1996 and 1998. The small
and stable SLC beam spot and the CCD-based vertex detector were used to
reconstruct B/Bbar decay vertices with high efficiency and purity, and to
provide measurements of the kinematic quantities used to calculate the B
energies in this novel technique. We measured the B/Bbar energies with good
efficiency and resolution over the full kinematic range. We measured moments of
the scaled energies of the B and Bbar hadrons vs. the opening angle between
them. By comparing these results with perturbative QCD predictions we tested
the ansatz of factorisation in heavy-quark production. A recent next-to-leading
order calculation reproduces the data.Comment: 17 pages, 6 figures; submitted to Physics Letters