A theoretical prediction for exclusive decays B→K(K*)ηc

The decay rates for the exclusive B decays B → Kηc and B → K*ηc are calculated in the context of the heavy quark effective theory. We obtain Γ(B → Kηc)/Γ(B → Kψ) = 1.6 ± 0.2 and Γ(B → K*ηc)/Γ(B → K*ψ) = 0.39 ± 0.04. These results lead to estimates BR(B → Kηc) = (0.11 ± 0.02)% and BR(B → K*ηc) = (0.05 ± 0.01)% if we use the central current experimental values for B → (K,K*)ψ branching ratios. (orig.)