Factorization and Sudakov Resummation in B -> gamma l nu

Abstract

We apply Soft-Collinear Effective Theory to prove at leading power in Lambda_QCD/m_b a factorization formula for the radiative leptonic decay B -> gamma l nu. Large logarithms entering the hard-scattering kernel are systematically resummed by a two-step perturbative matching procedure.

Comments: 3 pages, 1 figure; contribution to proceedings of "International Europhysics Conference on High Energy Physics" EPS (July 17th-23rd 2003) in Aachen; to appear in European Physical Journal C direct