Analysis of the Z(4430) as the First Radial Excitation of the Zc (3900)*

In this article, we take the Z c (3900) and Z(4430) as the ground state and the first radial excited state of the axial-vector tetraquark states with J PC = 1 +− , respectively, and study their masses and pole residues with the QCD sum rules by calculating the contributions of the vacuum condensates up to dimension-10 in a consistent way in the operator product expansion. The numerical result favors assigning the Z c (3900) and Z(4430) as the ground state and first radial excited state of the axial-vector tetraquark states, respectively.