Γ(b→ulν)/Γ(b→clν) from the end point of the lepton momentum spectrum in semileptonicBdecay

Abstract

We have used the measured yield of leptons near the end point of the momentum spectrum from semileptonic B decay to obtain an upper limit on Γ(b→ulν)/Γ(b→clν) and a corresponding limit on ‖$V_{\mathrm{ub}}$‖/‖$V_{\mathrm{cb}}$‖.