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

By using QCD Sum Rules, we found that the charged hidden charm tetraquark [c u][c̄ d̄] states with JP = 1⁻ and 2⁺ , which are possible quantum numbers of the newly observed charmonium-like resonance Zc(4025) , have masses of m1⁻ᶜ = (4.54 ± 0.20) \, GeV and m2⁺ᶜ = (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 m1⁻ᵇ = (10.97 ± 0.25) \, GeV and m2⁺ᵇ = (10.35 ± 0.25) \, GeV were obtained, which values are testable in future B-factories.