Tetraquarks with open charm flavor
Yaoyao Xue, Xin Jin, Hongxia Huang, Jialun Ping, Fan Wang
Abstract
Inspired by the recent report of the exotic states ${X}_{0}(2900)$ and ${X}_{1}(2900)$ with four different quark flavors in the ${D}^{\ensuremath{-}}{K}^{+}$ invariant-mass distributions of the decay process ${B}^{+}\ensuremath{\rightarrow}{D}^{+}{D}^{\ensuremath{-}}{K}^{+}$ by the LHCb Collaboration, we systematically investigate the tetraquarks composed of $ud\overline{s}\overline{c}$ with meson-meson and diquark-antidiquark structures in the quark delocalization color-screening model. We find that the ${X}_{0}(2900)$ can be interpreted as the molecular state $\overline{D}{\text{ }}^{*}{K}^{*}$ with $I{J}^{P}=0{0}^{+}$. Moreover, two bound states are obtained by the channel coupling calculation, with energies 2341.2 MeV for $I{J}^{P}=0{0}^{+}$ and 2489.7 MeV for $I{J}^{P}=0{1}^{+}$, respectively. We also extend our study to the $uc\overline{d}\overline{s}$ systems and find that there is no $S$-wave bound state, so the ${D}_{s0}(2317)$ cannot be identified as the $DK$ molecular state in the present calculation. Besides, several resonance states with the diquark-antidiquark configuration are possible in both $ud\overline{s}\overline{c}$ and $uc\overline{d}\overline{s}$ systems. The states composed of $ud\overline{s}\overline{b}$ are also possible open bottom tetraquark candidates. All of these open charm and open bottom bound states and resonances are worth investigating in future experiments.