Universality of nonperturbative QCD effects in radiative B-decays

We demonstrate, by an explicit one-loop calculation, that at leading twist the nonperturbative effects in B --> gammalv(l), B --> gammagamma and B --> gamma l(+)l(-) radiative decays are contained in a common multiplicative factor (A(B) (Egamma), where Egamma is the energy of the photon). We argue that this result holds also at higher orders. Ratios of the amplitudes for these processes do not depend on scales below the mass of the B-meson (M-B), and can be calculated as perturbative series in alpha(s)(M-B) (C) 2003 Elsevier Science B.V. All rights reserved.