Related papers: Resonance $X(6600)$
Recently the LHCb Collaboration announced the first observation of nontrivial structures in the double-$J/\psi$ mass spectrum in the mass range 6.2-7.2 GeV, and a theoretical coupled-channel analysis of these data performed in Phys. Rev.…
Inspired by recent measurement of possible fully charmed tetraquarks in LHCb Collaboration, we investigate the mass spectra of fully heavy tetraquarks $QQ \bar Q \bar Q$ in an extended relativized quark model. Our estimations indicate that…
In the present work, we construct the diquark-antidiquark type four-quark currents to investigate the mass spectrum of the ground state hidden-charm-hidden-strange tetraquark states with the quantum numbers $J^{PC}=0^{++}$, $1^{+-}$,…
The LHCb collaboration have recently updated their analysis of the resonant $J/\psi p$ mass spectrum in the decay $\Lambda_b^0 \to J/\psi p K^-$, making use of their combined Run 1 and Run 2 data. In the updated analysis, three narrow…
We study the decay properties of a $D(2900)$ state, with spin-parity $0^-$, whose existence was proposed in an earlier study of the $D K\bar K$ and coupled channel system. It was found in the former work that a $D$-meson appears with a mass…
Within the framework of the quark delocalization color screening model, a systematic investigation of the anticharmed-strange pentaquark system is performed using the resonance group method. The currently estimations predict three bound…
We calculate the masses of $\chi_{\rm c}(3P)$ states with threshold corrections in a coupled-channel model. The model was recently applied to the description of the properties of $\chi_{\rm c}(2P)$ and $\chi_{\rm b}(3P)$ multiplets [Phys.\…
In this article, we take the $X(5568)$ to be the scalar diquark-antidiquark type tetraquark state, study the hadronic coupling constant $g_{XB_s\pi}$ with the three-point QCD sum rules by carrying out the operator product expansion up to…
The semileptonic decays of the open charm-bottom axial-vector tetraquark $ Z_{s}=[cs][\overline{b}\overline{s}]$ to $X(4274)\overline{l} \nu_l$, $l=e, \mu, \tau $ are explored by means of the QCD three-point sum rule method. Both $Z_{s}$…
Treating the $X(4140)$ as a compact $J^{PC}=1^{++}$ $cs\bar{c}\bar{s}$ state and using its mass as a reference scale, we systematically estimate the masses of doubly heavy tetraquark states $QQ\bar{q}\bar{q}$ where $Q=c,b$ and $q=u,d,s$.…
We introduce a relative P-wave to construct the vector doubly-charm diquark $(\widetilde{V})$, therefore, the scalar and tensor four-quark currents to investigate the decay widths of the fully-charm tetraquark states with the…
In this article, we assume that the narrow structure X(4350) is a scalar $\bar{c}c-{D}_s^\ast {\bar {D}}_s^\ast$ mixing state, and study its mass using the QCD sum rules. The numerical result $M_X=(4.37\pm0.15)\,\rm{GeV}$ is in good…
We have systematically investigated the mass spectrum and rearrangement decay properties of the exotic tetraquark states with four different flavors using a color-magnetic interaction model. Their masses are estimated by assuming that the…
We have studied the strong decay properties of the recently observed $T^a_{c\bar s0}(2900)^{++/0}$ by considering it as a $cu\bar{d}\bar{s}/cd\bar{u}\bar{s}$ fully open-flavor tetraquark state with $I(J^P)=1(0^+)$. In the framework of QCD…
Very recently, the LHCb Collaboration reported a fully charmed tetraquark state $X(6900)$ in the invariant mass spectrum of $J/\psi$ pairs. If one $J/\psi$ meson is replaced with a fully charmed baryon, we obtain a fully charmed pentaquark…
The mass and decay width of the $\Theta^+(1540)$ with isospin 0 are investigated in a constituent quark model comprising $uudd\bar{s}$ quarks. The resonance state for the $\Theta^+$ is identified as a stable solution in correlated basis…
To understand the nature of $X(2075)$ and $X(2085)$ observed by the BESIII collaboration in the $p\bar{\Lambda}$ system, we systematically investigate the possibility that these states are compact hexaquark with triquark-antitriquark…
The spectroscopic parameters and decay channels of the axial-vector tetraquark $T_{bb;\overline{u}\overline{s}}^{-}$ (in what follows, $T_{b: \overline{s}}^{\mathrm{AV}}$) are explored using the quantum chromodynamics (QCD) sum rule method.…
The weak decays of the axial-vector tetraquark $T_{bb;\bar{u} \bar{d}}^{-}$ to the scalar state $Z_{bc;\bar{u} \bar{d}}^{0}$ are investigated using the QCD three-point sum rule approach. In order to explore the process $T_{bb; \bar{u}…
The $X(3872)$ could be a shallow $D\bar D^*$ bound state, a compact four-quark state, or a partially composite particle, i.e. a superposition of the two. We will review how these hypotheses could be tested experimentally, examining…