A Theoretical Prediction for Exclusive Decays $B \rightarrow K(K^*) η_c$

Abstract

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