Radiative Corrections to Radiative B Decays: Exclusive B -> V gamma at NLO

Abstract

We discuss a model-independent framework for the analysis of the radiative B-meson decays B -> K* gamma and B -> rho gamma based on the heavy-quark limit of QCD. We present a factorization formula for the treatment of B -> V gamma matrix elements involving charm (or up-quark) loops, which contribute at leading power in Lambda_QCD/m_B to the decay amplitude. Annihilation topologies are power suppressed, but still calculable in some cases. The framework of QCD factorization is necessary to compute exclusive b -> s(d) gamma decays systematically beyond the leading logarithmic approximation. Results to next-to-leading order in QCD and to leading order in the heavy-quark limit are given and phenomenological implications are discussed.

Comments: Talk presented at 6th International Symposium on Radiative Corrections (RADCOR) and 6th Workshop on Elementary Particle Theory (Loops and Legs), 8-13 September 2002, Kloster Banz, Germany; 5 pages, 7 figures