Factorization in B->V gamma Decays
Abstract
The factorization properties of the radiative decays B->V gamma are analyzed at leading order in 1/m_b using the soft-collinear effective theory. It is shown that the decay amplitudes can be expressed in terms of a B->V form factor evaluated at q^2=0, light-cone distribution amplitudes of the B and V mesons, and calculable hard-scattering kernels. The renormalization-group equations in the effective theory are solved to resum perturbative logarithms of the different scales in the decay process. Phenomenological implications for the B->K* gamma branching ratio, isospin asymmetry, and CP asymmetries are discussed, with particular emphasis on possible effects from physics beyond the Standard Model.
Cite
@article{arxiv.hep-ph/0503263,
title = {Factorization in B->V gamma Decays},
author = {Thomas Becher and Richard J. Hill and Matthias Neubert},
journal= {arXiv preprint arXiv:hep-ph/0503263},
year = {2008}
}
Comments
52 pages, 7 figures; references added and brief discussion of power corrections included; version to appear in Phys. Rev. D