We propose that the $Y(4260)$ particle recently announced by BABAR is the first orbital excitation of a diquark-antidiquark state $([cs][\overline{c}\overline{s}])$. Using parameters recently determined to describe the $X(3872)$ and $X(3940)$ we show that the $Y$ mass is compatible with the orbital excitation picture. A crucial prediction is that $Y(4260)$ should decay predominantly in $D_s{\overline{D}}_s$. The $Y(4260)$ should also be seen in $B$ nonleptonic decays in association with one kaon. We consider the full nonet of related four-quark states and their predicted properties. Finally, we comment on a possible narrow resonance in the same channel.

• Received 5 July 2005

DOI:https://doi.org/10.1103/PhysRevD.72.031502