Investigation of the tetraquark states $Qq\bar{Q}\bar{q}$ in the improved chromomagnetic interaction model

Abstract

In the framework of the improved chromomagnetic interaction model, we complete a systematic study of the $S$-wave tetraquark states $Qq\bar{Q}\bar{q}$ ($Q=c,b$, and $q=u,d,s$) with different quantum numbers, $J^{PC}=0^{+(+)}$, $1^{+(\pm )}$, and $2^{+(+)}$. The mass spectra of tetraquark states are predicted and the possible decay channels are analyzed by considering both the angular momentum and $\mathcal{C}$-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. Besides, based on the wave function of each tetraquark state, we find that the low-lying states of each $Qq\bar{Q}\bar{q}$ configuration have a large overlap to the $Q\bar{Q}$ and $q\bar{q}$ meson basis, instead of $Q\bar{q}$ and $q\bar{Q}$ meson basis. This indicates one can search these tetraquark states in future experiments via the channel of $Q\bar{Q}$ and $q\bar{q}$ mesons.

Comments: 11 pages, 9 figures, and 4 tables; accepted for publication in Chinese Physics C