Systematic approach to exclusive B→Vℓ+ℓ−, Vγ decays Original Research Article

We show — by explicit computation of first-order corrections — that the QCD factorization approach previously applied to hadronic two-body decays and to form factor ratios also allows us to compute non-factorizable corrections to exclusive, radiative B meson decays in the heavy quark mass limit. This removes a major part of the theoretical uncertainty in the region of small invariant mass of the photon. We discuss in particular the decays B→K∗γ and B→K∗ℓ+ℓ− and complete the calculation of corrections to the forward–backward asymmetry zero. The new correction shifts the asymmetry zero by 30%, but the result confirms our previous conclusion that the asymmetry zero provides a clean phenomenological determination of the Wilson coefficient C9.