Y(4260) and possible charmonium assignment

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Abstract
The newly reported Y(4260) becomes the second most massive state in the charmonium family. We argue that it displaces the ψ(4415) as the (largely) 4s vector charmonium state, recall s−d wave interference to explain the lack of a signal in e−e+→hadrons and suggest some further study avenues that can exclude exotic meson assignments. The absence of a J/ψKK mode can be understood, beyond phase space suppression, to be a consequence of chiral symmetry. We also provide a model calculation in this sector showing that, although forcing the fit somewhat (which suggests a small sea quark wave function component), the state can be incorporated in a standard scheme.