Rare radiative exclusive B decays in soft-collinear effective theory

ΛQCD/mb) and obtain the relevant operators to order λ in SCETI. These operators are constructed with or without spectator quarks including the four-quark operators contributing to annihilation and W -exchange channels. And we employ SCETII where the small parameter becomes of order ΛQCD/mb, and evolve the operators in order to compute the decay amplitudes for rare radiative decays in soft-collinear effective theory. We show explictly that the contributions from the annihilation channels and the W -exchange channels vanish at leading order in SCET. We present the factorized result for the decay amplitudes in rare radiative B decays at leading order in SCET, and at next-to-leading order in αs.