Understanding B⃗D^*-NN̅ and its implications

The CLEO Collaboration recently reported the observation of the B⁰→D^*-pn̄ mode at a rate of only a factor of 4–5 lower than B⁰→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_M^p,n measured from e⁺e^-→N̅ N and pp̅ →e⁺e^- processes, assuming factorization of the B⁰→D^*- transition and pn̄ pair production, we are able to account for up to 60% of the observed rate. The remainder is argued to arise from the axial vector current. The model is then applied to B decays to other mesons plus pn̄ modes and D^*- plus strange baryon pairs.