Reanalysis of the Z(c)(4020), Z(c)(4025), Z(c)(4050) and Z(c)(4250) as Tetraquark States with QCD Sum Rules

摘要

In this article, we calculate the contributions of the vacuum condensates up to dimension-10 in the operator product expansion, and study the C-gamma mu- C-gamma nu, type scalar, axial-vector and tensor tetraquark states in details with the QCD sum rules. In calculations, we use the formula mu = root M-x/y/z(2) - (2M(c))(2) to determine the energy scales of the QCD spectral densities. The predictions M J=2 = (4.02(-0.09) (+0.09)) GeV M(J)f = 1 = (4.02(-0.08) (+0.07)) GeV favor assiging the Z(c)(4020) and Z(c)a(4025) as the J(Pc) = 1+- or 2(++) diquark-antidiquark type tetraquark states, while the prediction MJ=0 = (3.85(-0.09)(+0.15)) GeV disfavors assigning the Z(4050) and Z(4250) as the JPc = 0(++) diquark-antidiquark type tetra quark states. Furthermore, we discuss the strong decays of the 0(++), 1(+-), 2(++) diquark-antidiquark type tetraquark states in details.