Interpretation of Zc(4025) as the hidden charm tetraquark states via QCD Sum Rules

By using QCD Sum Rules, we found that the charged hidden charm tetraquark [cu][ anti c anti d] states with JP = 1- and 2+, which are possible quantum numbers of the newly observed charmonium-like resonance Zc(4025), have masses of mc1- = (4.54 ± 0.20) GeV and mc2+ = (4.04 ± 0.19) GeV. The contributions up to dimension eight in the operator product expansion were taken into account in the calculation. The tetraquark mass of JP = 2+ state was consistent with the experimental data of Zc(4025), suggesting the Zc(4025) state to possess the quantum number of JP = 2+. Extending to the b-quark sector, the corresponding tetraquark masses mb1- = (10.97 ± 0.25) GeV and mb2+ = (10.35 ± 0.25) GeV were obtained, which values are testable in future B-factories. (orig.)