Extracting vertical bar V-ub vertical bar from the hadronic mass spectrum of inclusive B decays

Following a strategy introduced earlier by the authors, we show that it is possible to extract \V-ub\ from the cut hadronic mass spectrum of B decays without large systematic errors which usually arise from having to model th e Fermi motion of the heavy quark. We present a closed form expression for \V-ub\ / \V-ts\ which is accurate up to corrections of order alpha(s)(2), a lpha(s)rho, (Lambda/m(b))(2)/rho, where rho is the experimental cut (s(c)/m (b)(2)) on the hadronic mass used to veto charmed decays. Module duality vi olation errors, which are intrinsic to all inclusive predictions, we estima te the theoretical error in the extraction to be at the 5% level. (C) 2000 Elsevier Science B.V. All rights reserved.