Radiative $B\to K^{\ast }\gamma$ transition in QCD

Abstract

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

Comments: 11 pages, plus cover page, 1 figure (not included),Latex, BARI-TH/93-150, July 1993