Measurement of the inclusive charmless semileptonic branching fraction of beauty hadrons and a determination of vertical bar V-ub vertical bar at LEP

A measurement of the inclusive charmless semileptonic branching fraction of beauty hadrons, b --> X-u l nu, has been performed using almost two million hadronic Z decays collected by the L3 experiment at LEP, yielding the result: Br(b --> X-u l nu) = (3.3 +/- 1.0 +/- 1.7) x 10(-3). The first uncertainty is statistical and the second is systematic. The modulus of the Cabibbo-Kobayashi-Maskawa matrix element V-ub extracted from this measurement is: V-ub = (6.0(-1.0-1.9)(+0.8+1.4) +/- 0.2) x 10(-3), where the uncertainties are statistical, systematic and theoretical, respectively. (C) 1998 Elsevier Science B.V. All rights reserved.