Production of doubly charmed baryons in B decays
  We study the doubly charmed baryonic B decays $B\to \Xi_{c} \Lambda_{c}$ and $B\to \Lambda^{+}_{c} \Lambda^{-}_{c} K$, recently observed by BELLE. We find that the unexpected large branching ratios (BRs) could be ascribed to the final state interactions (FSIs), which are dictated by $B\to DD^{+}_{s}\to \Xi_{c} \Lambda^{+}_{c}$ and $B\to \bar D^0 D^{0} K\to \Lambda^{+}_{c} \Lambda^{-}_{c} K$. By utilizing the same mechanism, we predict that the BRs for $B^{+}\to \bar \Xi^{0}_{c} \Sigma^{+}_{c}$ and $B^{+} \to \Sigma^{\mp}_{c} \Lambda^{\pm}_{c} K^{+}$ decays could be as large as $BR(B^{+}\to \bar\Xi^{0}_{c} \Lambda^{+}_{c})$ and $10^{-4}$, respectively. In addition, extending the FSIs to the processes associated with the creation of the $s\bar s$ pair, $BR(B^{+}\to \bar \Omega_{c} \Xi^{+}_{c})$ at percent level is achievable. 
Chuan-Hung Chen