Spin-1 charmonium-like states in QCD sum rule

We study the possible spin-1 charmonium-like states by using QCD sum rule approach. We calculate the two-point correlation functions for all the local form tetraquark interpolating currents with $J^{PC}=1^{--},1^{-+},1^{++}$ and $1^{+-}$ and extract the masses of the tetraquark charmonium-like states. The mass of the $1^{--}$ $qc\bar{q}\bar{c}$ state is $4.6\sim 4.7$ GeV, which implies a possible tetraquark interpretation for Y(4660) meson. The masses for both the $1^{++}$ $qc\bar{q}\bar{c}$ and $sc\bar{s}\bar{c}$ states are $4.0\sim 4.2$ GeV, which is slightly above the mass of X(3872). For the $1^{-+}$ and $1^{+-}$ $qc\bar{q}\bar{c}$ states, the extracted masses are $4.5\sim 4.7$ GeV and $4.0\sim 4.2$ GeV respectively.