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Factorization in B->V gamma Decays

Thomas Becher·Richard J. Hill·Matthias Neubert
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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.

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Thomas Becher, Richard J. Hill, Matthias Neubert. 2005-11-03. Factorization in B->V gamma Decays. https://doi.org/10.1103/physrevd.72.094017

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