The rare $\bar{B}^0_{d} \to \phi\gamma$ decays in Standard Model and as a probe of R-parity violation

Abstract

We present the first study of the rare annihilation decay $\bar{B}^0_d \to \phi\gamma$ in the Standard Model. Using QCD factorization formalism, we find ${\cal B}(\bar{B}^0_d \to\phi\gamma)=3.6\times 10^{-12}$. The smallness of the decay rate in the Standard Model make the decay a sensitive probe of new physics contributions. As an example, we calculate the effects of R-parity violating couplings. Within the available upper bounds for $|\lambda^{''}_{i23}\lambda^{''}_{i12}|$ and $|\lambda^{'}_{i32}\lambda^{'*}_{i12}|$, ${\cal B}(\bar{B}^0_d \to\phi\gamma)$ could be enhanced to order of $10^{-9}\sim 10^{-8}$, which might be accessible at LHCB, B-TeV and the planning super high luminosity B factories at KEK and SLAC.