A new decay mode of higher charmonium

Abstract

We calculate the Λ cΛ ¯ c partial decay width of the excited vector charmonium states around 4.6 GeV with the quark pair creation model. We find that the partial decay width of the Λ cΛ ¯ c mode can reach up to several MeV for ψ(4S,5S,6S). In contrast, the partial Λ cΛ ¯ c decay width of the states ψ(3D,4D,5D) is less than one MeV. If the enhancement Y(4630) reported by the Belle Collaboration in Λ cΛ ¯ c invariant-mass distribution is the same structure as Y(4660), the Y(4660) resonance is most likely to be a S-wave charmonium state.