Chinese Acad Sci, Inst High Energy Phys, Beijing 100049, Peoples R China
The pure annihilation type decays B-d(0) -> phi gamma and B-s -> rho gamma receive only colour suppressed penguin contributions with a very small branching ratio in the standard model. When we include the previously neglected electromagnetic dipole operator, the branching ratios can be enhanced to R(B-d(0) -> phi gamma) similar or equal to 1 X 10(-11) and R(B-s -> rho gamma) similar to (6 - 16) x 10(-10), which are one order magnitude larger than previous study using the QCD factorization approach. The new effect can also give a large contribution, of order 10(-9), to transverse polarization of B-s -> phi rho and B-s -> omega phi, which is comparable to the longitudinal part. These effects can be detected in the LHCb experiment and the super-B factories.