Key points are not available for this paper at this time.
In this work, we choose diquark-antidiquark type four-quark currents with an explicit P-wave to study the ground states and first radial excitations of the hidden-charm tetraquark states with the quantum numbers J^PC=1^--. And we obtain the lowest vector tetraquark masses and make possible assignments of the existing Y states. There indeed exists a hidden-charm tetraquark state with the J^PC=1^-- at the energy about 4. 75\, GeV as the first radial excitation to account for the BESIII data.
Zhi-Gang Wang (Tue,) studied this question.