Spin-1 charmonium-like states in QCD sum rule

¹ Department of Physics and State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing 100871, China
² Technology and Center of High Energy Physics, Peking University, Beijing 100871, China

^a e-mail: boya@pku.edu.cn
^b e-mail: zhusl@pku.edu.cn

Abstract

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 these tetraquark charmonium-like states. The mass of the 1⁻⁻ qc$\overline{q}$$\overline{c}$ state is 4.6 ~ 4.7 GeV, which implies a possible tetraquark interpretation for Y(4660) meson. The masses for both the 1⁺⁺ qc$\overline{q}$$\overline{c}$ and sc$\overline{s}$$\overline{c}$ states are 4.0 ~ 4.2 GeV, which is slightly above the mass of X(3872). For the 1⁻⁺ and 1⁺⁻ qc$\overline{q}$$\overline{c}$ states, the extracted masses are 4.5 ~ 4.7 GeV and 4.0 ~ 4.2 GeV respectively.