Tetraquarks with open charm flavor

Inspired by the recent report of the exotic states X-0(2900) and X-1(2900) with four different quark flavors in the D- K+ invariant-mass distributions of the decay process B+ -> D+D-K+ by the LHCb Collaboration, we systematically investigate the tetraquarks composed of ud (d) over bar(s) over bar with meson-meson and diquark-antidiquark structures in the quark delocalization color-screening model. We find that the X 0o2900THORN can be interpreted as the molecular state (D) over bar*(K) over bar with IJ(P) = 00(+). Moreover, two bound states are obtained by the channel coupling calculation, with energies 2341.2 MeV for IJP = 00+ and 2489.7 MeV for IJ(P) = 01(+), respectively. We also extend our study to the uc d 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 (s) over bar(c) over bar and uc (d) over bar(s) over bar systems. The states composed of ud (s) over bar (b) over bar 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.

Automated summary

Inspired by recent reports of exotic states with four different quark flavors, we systematically investigate tetraquark systems in the quark delocalization color-screening model, proposing possible molecular and bound state interpretations.