Radiative $B \to K^* γ$ transition in QCD

Abstract

We evaluate the branching ratios of the radiative decays $B \to K^* γ$, and $B \to K_1 γ$ in the framework of three-point function QCD sum rules. We find: $ Γ(B \to K^* γ) / Γ(b \to s γ) = 0.17 \pm 0.05$ and $ Γ(B \to K_1 γ) / Γ(b \to s γ) = 0.30 \pm 0.15$. We also study, in the infinite quark mass limit, the connection between the form factor of the radiative $B \to K^* γ$ transition and the weak hadronic form factors entering the semileptonic B-meson decays.