Observation of Semileptonic Charmless B Meson Decays

A detailed study of the lepton momentum spectrum in υ (4 S ) decays has been made using the ARGUS detector at the DORIS II e + e − storage ring at DESY. In the region from 2.3 to 2.6 GeV/ c , which is above the endpoint for contributions from B decays via b → c transitions, we observe 41±10 events in excess of known backgrounds. These events are interpreted as a signal for b → u transitions. A model dependent value of 0.10±0.01 is obtained for the ratio of Cabibbo-Kobayashi-Maskawa matrix elements | V ub |/| V cv| , using the Altarelli et al. model.

electron positron: colliding beams
electron positron: annihilation
Upsilon(10570): electroproduction
B: pair production
B: semileptonic decay
final state: (0charmed particle)
momentum spectrum: (lepton)
CKM matrix matrix
ARGUS
experimental results

References(16)

Figures(0)

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