Investigation of the tetraquark states Qq(Q)over-bar(q)over-bar in the improved chromomagnetic interaction model

In the framework of the improved chromomagnetic interaction model, we complete a systematic study of the S-wave tetraquark states Qq (Q) over bar(q) over bar (Q = c,b, and q= u,d,s) with different quantum numbers: J(PC) = 0(+(+)), 1(+(+/-)) and 2(+(+/-)). The mass spectra of tetraquark states are predicted, and the possible decay channels are analyzed by considering both the angular momentum and C-parity conservation. The recently observed hidden-charm tetraquark states with strangeness, such as Z(cs)(3985)(-),X(3960), and Z(cs)(4220)(+), can be well explained in our model. Additionally, according to the wave function of each tetraquark state, we find that the low-lying states of each Qq (Q) over bar(q) over bar configuration have a large overlap to the Q (Q) over bar and q (q) over bar meson basis, instead of the Q (q) over bar and q(Q)over bar> meson basis. This indicates that one can search these tetraquark states in future experiments via the channel of Q (Q) over bar and q (q) over bar mesons.