Note on the extraction of |Vub| using radiative B decays

Abstract The element | V ub | of the quark mixing matrix can be extracted with small theoretical uncertainties by combining weighted integrals over the endpoint regions of the lepton spectrum in B → X u lν decays and the photon spectrum in B → X s γ decays. The perturbative corrections to this determination are computed at next-to-leading order including operator mixing, which has an important impact. The effect of Sudakov resummation is shown to be numerically insignificant.