A new decay mode of higher charmonium

Abstract

We calculate the $Λ_c\barΛ_c$ 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 $Λ_c\barΛ_c$ mode can reach up to several MeV for $ψ(4S,~5S,~6S)$. In contrast, the partial $Λ_c\barΛ_c$ 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 $Λ_c\barΛ_c$ invariant-mass distribution is the same structure as $Y(4660)$, the $Y(4660)$ resonance is most likely to be a $S$-wave charmonium state.

8 pages, 4 figures