Y(4260) as a mixed charmonium-tetraquark state
Abstract
Using the QCD sum rule approach we study the Y(4260) state assuming that it can be described by a mixed charmonium-tetraquark current with
J
PC
=
1
−−
quantum numbers. For the mixing angle around
θ≈(53.0±0.5
)
0
, we obtain a value for the mass which is in good agreement with the experimental mass of the Y(4260). However, for the decay width we find the value $\Ga_Y \approx (1.0\pm 0.2)$ MeV which is not compatible with the experimental value $\Ga \approx (88\pm 23)$ MeV. Therefore, we conclude that, although we can explain the mass of the Y(4260), this state cannot be described as a mixed charmonium-tetraquark state since, with this assumption, we can not explain its decay width.