Factorization of radiative leptonic decays of B- and D- mesons

In this work, we study the factorization of the radiative leptonic decays of B- and D- mesons, the contributions of the order O(Lambda(QCD)/m(Q)) are taken into account. The factorization is proved to be valid explicitly at the order O(alpha(S)Lambda(QCD)/m(Q)). The hard kernel is obtained. The numerical results are calculated using the wave-function obtained in relativistic potential model. The O(Lambda(QCD)/m(Q)) contribution is found to be very important, the correction to the decay amplitudes of B- --> gamma e (v) over bar is about 20%-30%. For D mesons, the O(Lambda(QCD)/m(Q)) contributions are more important. (C) 2014 The Authors. Published by Elsevier B.V.