Research Information System
Physical Review D, vol.107, no.9, 2023 (SCI-Expanded)
Two near-threshold peaking structures with spin-parities JPC=0++ were recently discovered by the LHCb Collaboration in the Ds+Ds- invariant mass distribution of the decay B+→Ds+Ds-K+. The first of them is the resonance X(3960), whereas the second one, X0(4140), is a structure with the mass around 4140 MeV. To explore their natures and model them, we study the hadronic molecule M=Ds+Ds- and calculate its mass, current coupling, and width. The mass and current coupling of the molecule are extracted from the QCD two-point sum rule analyses by taking into account vacuum condensates up to dimension 10. To evaluate its full width, we consider the processes M→Ds+Ds-, M→ηcη(′), and M→J/ψφ. Partial widths of these decays are determined by the strong couplings gi,i=1, 2, 3, 4 at vertices MDs+Ds-, Mηcη(′), and MJ/ψφ. They are computed by means of the three-point sum rule method. Predictions for the mass m=(4117±85) MeV and width ΓM=(62±12) MeV of the molecule M are compared with the corresponding LHCb data, and also with our results for the diquark-antidiquark state X=[cs][c¯s¯]. We argue that the structure X0(4140) may be interpreted as the hadronic molecule Ds+Ds-, whereas the resonance X(3960) can be identified with the tetraquark X.