Bonn 2001 – wissenschaftliches Programm
T 205.4: Vortrag
Dienstag, 27. März 2001, 14:45–15:00, HS IV
Measurement of BR(c → l) in ALEPH — •Aretina David1, Duccio Abbaneo2, and Kay Hüttmann1 — 1Max-Planck-Institut für Physik (Werner-Heisenberg-Institut), Föhringer Ring 6, 80805 München — 2CERN, EP Division, CH-1211 Geneve 23
In view of the measurement of BR(c → l) with the ALEPH detector, a dedicated charm selection has been designed. It is based on fully and partially reconstructed D0,D+,D*+ candidates. Variables which distinguish candidates produced in charm events from candidates produced in b decays are combined, by means of a neural network, into a single discriminating variable. Similarly, a variable which rejects combinatorial background in light quark events is constructed. These two variables improve substantially the charm purity of the sample selected, which is crucial for the measurement of the semileptonic branching ratio.