Insights into the inner structures of the fully charmed tetraquark state $X(6900)$

Abstract

The recently discovered fully charmed tetraquark candidate $X(6900)$ is analyzed within the frameworks of effective-range expansion, compositeness relation and width saturation, and a coupled multichannel dynamical study. By taking into account constraints from heavy-quark spin symmetry, the coupled-channel amplitude including the $J/\psi J/\psi ,{\chi }_{c0}{\chi }_{c0}$ and ${\chi }_{c1}{\chi }_{c1}$ is constructed to fit the experimental di-$J/\psi$ event distributions around the energy region near $6.9$ GeV. Another dynamical two-coupled-channel amplitude with the $J/\psi J/\psi$ and $\psi (3770)J/\psi$ is also considered to describe the same datasets. The three different theoretical approaches lead to similar conclusions that the two-meson components do not play dominant roles in the $X(6900)$. Our determinations of the resonance poles in the complex energy plane from the refined coupled-channel study are found to be consistent with the experimental analyses. The coupled-channel amplitudes also have another pole corresponding to a narrow resonance $X(6825)$ that we predict sitting below the ${\chi }_{c0}{\chi }_{c0}$ threshold and of molecular origin. We give predictions to the line shapes of the ${\chi }_{c0}{\chi }_{c0}$ and ${\chi }_{c1}{\chi }_{c1}$ channels, which could provide a useful guide for future experimental measurements.

22 pages, 3 figures. To match the published version

References in corpus (18)

• Anatomy of the newly observed hidden-charm pentaquark states: $P_c(4312)$, $P_c(4440)$ and $P_c(4457)$
• Comprehensive analysis of the wave function of a hadronic resonance and its compositeness
• The Simple Spectrum of $c\bar{c}c\bar{c}$ States in the Dynamical Diquark Model
• Doubly-hidden scalar heavy molecules and tetraquarks states from QCD at NLO
• Diffusion Monte Carlo calculations of fully-heavy (multiquark) bound states
• Coupled-channel interpretation of the LHCb double-$J/\psi$ spectrum and hints of a new state near the $J/\psi J/\psi$ threshold
• Fully-heavy tetraquark spectra and production at hadron colliders
• Masses of the $QQ\bar{Q}\bar{Q}$ tetraquarks in the relativistic diquark--antidiquark picture
• Interplay of quark and meson degrees of freedom in a near-threshold resonance
• Interpretation of structure in the di-$J/\psi$ spectrum
• On the mechanism of $T_{4c}(6900)$ tetraquark production
• Fully-heavy tetraquarks in strongly interacting medium
• $0^{+}$ fully-charmed tetraquark states
• The possible tetraquark states $cc\bar{c}\bar{c}$ observed by the LHCb experiment
• Producing fully-charm structures in the $J/\psi$-pair invariant mass spectrum
• XYZ spectroscopy at electron-hadron facilities: Exclusive processes
• Discovery potential for the LHCb fully-charm tetraquark $X(6900)$ state via $\bar{p}p$ annihilation reaction
• Doubly charmed multibaryon systems

Cited by in corpus (39)

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• Higher fully-charmed tetraquarks: Radial excitations and P-wave states
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• Fully heavy pentaquarks
• Benchmark calculations of fully heavy compact and molecular tetraquark states
• A unified description of the hidden-charm tetraquark states $Z_{cs}(3985)$, $Z_c(3900)$ and $X(4020)$
• Heavy Flavour Physics and CP Violation at LHCb: a Ten-Year Review
• The lineshape of the compact fully heavy tetraquark
• Going in quest of potential tetraquark interpretations for the newly observed $T_{\psi \psi }$ states in light of the diquark-antidiquark scenarios
• Exotic fully-heavy $Q\bar{Q}Q\bar{Q}$ tetraquark states in $8_{[Q\bar{Q}]}\otimes 8_{[Q\bar{Q}]}$ color configuration
• Study of $X(6900)$ with unitarized coupled channel scattering amplitudes
• NLO results with operator mixing for fully heavy tetraquarks in QCD sum rules
• Fully-heavy structures in the invariant mass spectrum of $J/\psi \psi (3686)$, $J/\psi \psi (3770)$, $\psi (3686)\psi (3686)$, and $J/\psi {\rm Y}(1S)$ at hadron colliders
• X(6200) as a compact tetraquark in the QCD string model
• Decay behaviors of the fully-bottom and fully-charm tetraquark states
• Fully heavy pentaquark states in constituent quark model
• Triply-heavy tetraquarks in an extended relativized quark model
• Improved understanding of the peaking phenomenon existing in the new di-$J/\psi$ invariant mass spectrum from the CMS Collaboration
• The two-photon decay of X(6900) from light-by-light scattering at the LHC
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