Understanding $B\to D^{*-}N\bar{N}$ and Its Implications

Abstract

The CLEO Collaboration recently reported the observation of the $B^0\to D^{*-}p\bar{n}$ mode at a rate only a factor of 4--5 lower than $B^0\to D^{*-}ρ^+$ and $D^{*-}π^+$. We try to understand this with a factorization approach of current produced nucleon pairs. The baryon weak vector current form factors are related by isospin rotation to nucleon electromagnetic form factors. By using $G^{p,n}_M$ measured from $e^+e^-\to \bar{N}N$ and $p\bar{p}\to e^+e^-$ processes, assuming factorization of the $B^0\to D^{*-}$ transition and the $p\bar n$ pair production, we are able to account for up to 60% of the observed rate. The remainder is argued to arise from the axial current. The model is then applied to B decays to other mesons plus $p\bar{n}$ modes and $D^{*-}$ plus strange baryon pairs.