B→K*γin the light-cone QCD sum rule

A new estimate of the electromagnetic penguin operator contribution to $\overrightarrow{B}{K}^{*}\gamma$ is proposed by using the light-cone QCD sum rule. We improve the previous investigation of Ali, Braun and Simma by proper choices of the current operators in the correlator. The reasonable estimates of the $b$-quark pole mass $m_b$ and decay constant $f_B$ are also given. Numerically, we find that the form factor $F^{\overrightarrow{B}{K}^{*}}\mathrm{}\left(0\right)=0.34\mathrm{}\pm 0.05$ and the branching ratio $B\left(\overrightarrow{B}{K}^{*}\gamma \right)=(5.1\mathrm{}\pm 1.7)\times {10}^{-5}$, with a $b$-quark pole mass $m_b=4.7\mathrm{}$–4.9 GeV. Our results are different from those of Ali et al., but the resulting branching ratio is still comparable with the experimental observation.