$B_s (B_d) \to γν\bar ν$ }

Abstract

We study the loop induced rare decays $B_s(B_d)\toγν\barν$ within the standard model. Both constituent quark model and pole model are used and the branching ratios turn out to be of the orders of $10^{-8}$ for $B_s\to γν\bar ν$ and $10^{-9}$ for $B_d \to γν\bar ν$. These processes can be served to determine the decay constants of $B_s$ and $B_d$.