B -> V gamma at NLO from QCD Factorization

Abstract

We discuss the exclusive radiative B-meson decays B -> K* gamma and B -> rho gamma in a model-independent manner. The analysis is based on the heavy-quark limit of QCD. This allows a factorization of perturbatively calculable contributions to the B -> V gamma matrix elements from non-perturbative form factors and universal light-cone distribution amplitudes. These results allow us to compute exclusive b -> s(d) gamma decays systematically beyond the leading logarithmic approximation. We present results for these decays complete to next-to-leading order in QCD and to leading order in the heavy-quark limit. Phenomenological implications for various observables of interest are discussed, including direct CP violation and isospin breaking effects.

Comments: Invited talks given at the Workshop on Exclusive B Decays, 20-22 July 2001, Regensburg and at the 9th International Symposium on Heavy Flavor Physics (HF9), 10-13 September 2001, Caltech, Pasadena. To be published in the proceedings of HF9, edited by Anders Ryd