Mass spectra and decays of open-heavy tetraquark states

Abstract

The observation of the exotic states ${X}_{0,1}(2900)$ with four open flavors by the LHCb Collaboration has promoted great interest in searching for the open-charm and open-bottom tetraquark states. In this work, we perform a systematic study of the open-heavy tetraquark systems $qq\overline{q}\overline{Q}$ ($q=u$, $d$, $s$ and $Q=c$, $b$) within the improved chromomagnetic interaction model. The mass spectra and color-spin wave functions of $S$-wave open-heavy tetraquark states with quantum numbers ${J}^{P}={0}^{+}$, ${1}^{+}$, and ${2}^{+}$ are calculated. A number of compact tetraquark states are predicted in both open-charm and open-bottom systems. The two-body decay properties of these tetraquark states are phenomenologically analyzed. Our results suggest that the exotic open-charm state ${X}_{0}(2900)$ observed by the LHCb Collaboration is likely a compact tetraquark state with quantum number $I{J}^{P}=0{0}^{+}$ (isospin singlet). For the open-bottom systems, our results also suggest a candidate for the exotic state ${X}^{\ifmmode\pm\else\textpm\fi{}}(5568)$ reported by the D0 Collaboration. The other tetraquark states predicted in this work may also be examined in future experiments.