Fully-heavy tetraquark states and their evidences in the LHC observations

Abstract

Stimulated by the exciting progress on the observations of the fully-charmed tetraquarks at LHC, we carry out a combined analysis of the mass spectra and fall-apart decays of the $1S$-, $2S$-, and $1P$-wave $cc\bar{c}\bar{c}$ states in a nonrelativistic quark model (NRQM). It is found that the $X(6600)$ structure observed in the di-$J/\psi$ invariant mass spectrum can be explained by the $1S$-wave state $T_{(4c)0^{++}}(6550)$. This structure may also bear some feed-down effects from the higher $2S$ and/or $1P$ tetraquark states. The $X(6900)$ structure observed in both the di-$J/\psi$ and $J/\psi \psi (2S)$ channels can be naturally explained by the $2S$-wave state $T_{(4c)0^{++}}(6957)$. The small shoulder structure around $6.2-6.4$ GeV observed at CMS and ATLAS may be due to the feed-down effects from some $1P$-wave states with $C=-1$ and/or some $2S$-wave states with $J^{PC}=0^{++}$. Other decay channels are implied in such a scenario and they can be investigated by future experimental analyses. Considering the large discovery potential at LHC, we also present predictions for the $bb\bar{b}\bar{b}$ states which can be searched for in the future.

14 pages, 3 figures, more details about the spectrum and decays are included

References in corpus (5)

• Multiquark Resonances
• Pentaquark and Tetraquark states
• Exotics: Heavy Pentaquarks and Tetraquarks
• Charmonium spectrum and their electromagnetic transitions with higher multipole contributions
• Exotic meson-meson molecules and compact four--quark states

Cited by in corpus (23)

• Fully-heavy tetraquark spectra and production at hadron colliders
• Coupled-channel interpretation of the LHCb double-$J/\psi$ spectrum and hints of a new state near the $J/\psi J/\psi$ threshold
• Towards the understanding of fully-heavy tetraquark states from various models
• Masses of the $QQ\bar{Q}\bar{Q}$ tetraquarks in the relativistic diquark--antidiquark picture
• Interpretation of structure in the di-$J/\psi$ spectrum
• Gluonic Tetracharm Configuration of $X(6900)$
• Insights into the inner structures of the fully charmed tetraquark state $X(6900)$
• Producing fully-charm structures in the $J/\psi$-pair invariant mass spectrum
• Higher fully-charmed tetraquarks: Radial excitations and P-wave states
• Fully-heavy tetraquark production by $\gamma \gamma$ interactions in hadronic collisions at the LHC
• Fully-strange tetraquark $ss\bar{s}\bar{s}$ spectrum and possible experimental evidence
• Discovery potential for the LHCb fully-charm tetraquark $X(6900)$ state via $\bar{p}p$ annihilation reaction
• Is $X(7200)$ the heavy anti-quark diquark symmetry partner of $X(3872)$?
• Exotic fully-heavy $Q\bar{Q}Q\bar{Q}$ tetraquark states in $8_{[Q\bar{Q}]}\otimes 8_{[Q\bar{Q}]}$ color configuration
• 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
• Decay behaviors of the fully-bottom and fully-charm tetraquark states
• The two-photon decay of X(6900) from light-by-light scattering at the LHC
• Inclusive production of fully-charmed $1^{+-}$ tetraquark at $\mathbf{B}$ factory
• The bosonic algebraic approach applied to the $[QQ][\bar{Q}\bar{Q}]$ tetraquarks
• Flavor Exotic Triply-Heavy Tetraquark States in AdS/QCD Potential
• Pseudoscalar charmonium pair interactions via the Pomeron exchange mechanism
• Mass spectra for the $cc\bar{b}\bar{b}$/$bb\bar{c}\bar{c}$ tetraquark states
• Searching for fully-heavy tetraquark states in QCD moment sum rules