Recent results of experimental studies of hadronic decays of charmonium states using the BES detector are reported. A number of puzzling features are observed. Foremost among these is the large discrepancy between the decay rates for J/ψ and ψ(2S) decays to ρπ and [Formula: see text] final states, first observed by the Mark II experiment. We find suppressions for ψ(2S) decays to these modes of factors in excess of sixty and twenty, respectively. Similar, although less dramatic, suppressions of vector plus tensor meson final states are also observed. No suppression is seen for axialvector plus pseudoscalar meson decays, but a strong flavor-SU(3) violation is seen in [Formula: see text] final states that has an opposite character for the J/ψ and ψ(2S).
Semileptonic $$B_c$$ meson decays to S-wave charmonium states