An analysis of Cabibbo-favored two-body decays of charmed mesons with ηor η' in the final state

We have carried out a study of Cabibbo-favored favored two-body decays of D0 and D+s involving η and η' in the final state, D0 → (η,η') anti K0, D0 → (η,η') anti K*0 and D+s → (η,η')π+,D+s → (η,η')ρ+. We have introduced an annihilation term wherever admissible, and investigated its size if it were to bridge the gap between theory and experiment in each case. We have also related the semileptonic rates for D+s → (η,η')e+ν to those of the hadronic rates for D+s → (η,η')π+ and unveiled a puzzle. We offer a possible solution. (orig.)