Aubert, B (reprint author), Phys Particules Lab, F-74941 Annecy Le Vieux, France.
We report two novel determinations of vertical bar V-ub vertical bar with reduced model dependence, based on measurements of the mass distribution of the hadronic system in semileptonic B decays. Events are selected by fully reconstructing the decay of one B meson and identifying a charged lepton from the decay of the other B meson from Y(4S) -> B (B) over bar events. In one approach, we combine the inclusive (B) over bar -> X(u)l (v) over bar rate, integrated up to a maximum hadronic mass m(X) < 1.67 GeV/c(2), with a measurement of the inclusive B -> X-s gamma photon energy spectrum. We obtain vertical bar V-ub vertical bar = (4.43 +/- 0.38(stat) +/- 0.25(syst) +/- 0.29(theo)) x 10(-3). In another approach we measure the total (B) over bar -> X(u)l (v) over bar rate over the full phase space and find vertical bar V-ub vertical bar = 3.84 +/- 0.70(stat) +/- 0.30(syst) +/- 0.10(theo)) x 10(-3).