Bound-state effects inB→K*γ

Applying perturbative QCD methods recently seen to give a good description of the two-body hadronic decays of the B meson, we address the question of bound-state effects on the decay B→${\mathit{K}}^{\mathrm{*}}$γ. Consistent with most analyses, we demonstrate that gluonic penguin diagrams, with photonic bremsstrahlung off a quark, change the decay rate by only a few percent. Using an asymptotic distribution amplitude for the ${\mathit{K}}^{\mathrm{*}}$ and just the standard model, we can obtain a branching ratio of a few ×${10}^{\mathrm{-}5}$, consistent with the observed rate.