B --> K$*\gamma$ from hybrid sum rule

Using the {\it hybrid} moments-Laplace sum rule (HSR), which is well-defined for M_b \rar \infty, in contrast with the popular double Borel (Laplace) sum rule (DLSR), which blows up in this limit when applied to the heavy-to-light processes, we show that the form factor of the B \rar K^* \ \gamma radiative transition is dominated by the light-quark condensate for M_b \rar \infty and behaves like \sqrt M_b. The form factor is found to be F^{B\rar K^*}_1(0) \simeq (30.8 \pm 1.3 \pm 3.6 \pm 0.6)\times 10^{-2}, where the errors come respectively from the procedure in the sum rule analysis, the errors in the input and in the SU(3)_f-breaking parameters. This result leads to Br(B\rar K^* \ \gamma) \simeq (4.45 \pm 1.12) \times 10^{-5} in agreement with the recent CLEO data. Parametrization of the M_b-dependence of the form factor including the SU(3)_f-breaking effects is given in (26), which leads to F^{B\rar K^*}_1(0)/ F^{B\rar \rho}_1(0) \simeq (1.14 \pm 0.02).