Y(4260) and possible charmonium assignment

Abstract

The newly reported Y(4260) becomes the second most massive state in the charmonium family. We argue that it displaces the 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= KK 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