The lineshape of the compact fully heavy tetraquark

Abstract

Hadrons and their distributions are the most direct observables in experiment, which would shed light on the non-perturbative mystery of quantum chromodynamics (QCD). As the result, any new hadron will challenge our current knowlege on the one hand, and provide additional inputs on the other hand. The fully heavy $cc\bar{c}\bar{c}$ system observed by LHCb recently opens a new era for hadron physics. We first extract the internal structure of the fully heavy tetraquarks directly from the experimental data, within the compact tetraquark picture. By fitting to the di-$J/\psi$ lineshape, we find that the $X(6900)$ is only cusp effect from the $J/\psi \psi (3770)$ channel. In addition, there is also a cusp slightly below $6.8\mathrm{GeV}$ stemming from the $J/\psi {\psi }^{\prime }$ channel. The two $0^{++}$ tetraquarks behave as two resonances above the di-${\eta }_c$ and di-$J/\psi$ threshold, respectively. The $2^{++}$ state is a bound state below the di-$J/\psi$ threshold. Furthermore, we find that the $X_{0^{++}}(6035)$ shows a significant structure in the di-${\eta }_c$ lineshape even after the coupled channel effect. This is an unique feature which can distinguish compact $cc\bar{c}\bar{c}$ tetraquark from the loosely hadronic molecules.

arXiv comment12 pages, 6 figures. accepted by PRD

References in corpus (64)

• Hadronic molecules
• The hidden-charm pentaquark and tetraquark states
• The $XYZ$ states: experimental and theoretical status and perspectives
• Pentaquark and Tetraquark states
• Heavy-Quark QCD Exotica
• Evidence that the a0(980) and f0(980) are not elementary particles
• Observation of structure in the $J/\psi$-pair mass spectrum
• A review of the open charm and open bottom systems
• Threshold cusps and triangle singularities in hadronic reactions
• Observation of B_c Mesons in p-bar p Collisions at sqrt{s} = 1.8 TeV
• $QQ\bar{Q}\bar{Q}$ states: masses, production, and decays
• Hunting for exotic doubly hidden-charm/bottom tetraquark states
• Heavy-flavored tetraquark states with the $QQ\bar{Q}\bar{Q}$ configuration
• Spectrum of fully-heavy tetraquarks from a diquark+antidiquark perspective
• Tetra- and penta-quark structures in the constituent quark model
• Precise predictions of charmed-bottom hadrons from lattice QCD
• Masses of fully heavy tetraquarks $QQ\bar{Q}\bar{Q}$ in an extended relativized quark model
• Tetraquarks composed of 4 heavy quarks
• All-heavy tetraquarks
• QCD Sum Rules Approach to the $X,Y$ and $Z$ States
• Heavy tetraquarks in the relativistic quark model
• Spectrum of the fully-heavy tetraquark state $QQ{\bar{Q}}^{\prime }{\bar{Q}}^{\prime }$
• Coupled-channel interpretation of the LHCb double-$J/\psi$ spectrum and hints of a new state near the $J/\psi J/\psi$ threshold
• Heavy hadronic molecules with pion exchange and quark core couplings: a guide for practitioners
• Fully-heavy tetraquark spectra and production at hadron colliders
• Towards the understanding of fully-heavy tetraquark states from various models
• A study of $cc\bar{c}\bar{c}$ tetraquark decays in 4 muons and in $D^{(\ast )}{\bar{D}}^{(\ast )}$ at LHC
• Systematics of fully heavy tetraquarks
• On the nature of near-threshold bound and virtual states
• Masses of the $QQ\bar{Q}\bar{Q}$ tetraquarks in the relativistic diquark--antidiquark picture
• Spectroscopy of triply-charmed baryons from lattice QCD
• Strong decays of fully-charm tetraquarks into di-charmonia
• Interpretation of structure in the di-$J/\psi$ spectrum
• Scalar Fully-heavy Tetraquark States $Q{Q}^{\prime }\bar{Q}\overline{Q^{\prime }}$ in QCD Sum Rules
• On the mechanism of $T_{4c}(6900)$ tetraquark production
• Fully-heavy tetraquarks in strongly interacting medium
• Gluonic Tetracharm Configuration of $X(6900)$
• Search for $bb\bar{b}\bar{b}$ tetraquark decays in 4 muons, $B^{+}{B}^{-}$, $B^0{\bar{B}}^0$ and $B_s^0{\bar{B}}_s^0$ channels at LHC
• Masses of doubly heavy-quark baryons in an extended chromomagnetic model
• $0^{+}$ fully-charmed tetraquark states
• Tetraquark state $X(6900)$ and the interaction between diquark and antidiquark
• Measurement of the ${\rm Y}$(1S) pair production cross section and search for resonances decaying to ${\rm Y}$(1S)${\mu }^{+}{\mu }^{-}$ in proton-proton collisions at $\sqrt{s}=$ 13 TeV
• Search for beautiful tetraquarks in the ${\rm Y}(1S)\mu \mu$ invariant-mass spectrum
• Tetraquark candidates in the LHCb's di-$J/\psi$ mass spectrum
• General considerations on the nature of $Z_b(10610)$ and $Z_b(10650)$ from their pole positions
• Insights into the inner structures of the fully charmed tetraquark state $X(6900)$
• Nature of $X(6900)$ and its production mechanism at LHCb
• Is the existence of a $J/\psi J/\psi$ bound state plausible?
• Study of charmonium-like and fully-charm tetraquark spectroscopy
• Exotic resonances of fully-heavy tetraquarks in a lattice-QCD insipired quark model
• Spectroscopy of ${\mathbf{B}}_{\mathbf{c}}$ mesons and the possibility of finding exotic ${\mathbf{B}}_{\mathbf{c}}$-like structures
• Hunting for states in the recent LHCb di-$J/\psi$ invariant mass spectrum
• Higher mass spectra of the fully-charmed and fully-bottom tetraquarks
• Mass spectra and wave functions of $T_{QQ\bar{Q}\bar{Q}}$ tetraquarks
• Producing fully-charm structures in the $J/\psi$-pair invariant mass spectrum
• Deciphering the recently discovered tetraquark candidates around 6.9 GeV
• Prediction of the Omega_bbb mass from lattice QCD
• Higher fully-charmed tetraquarks: Radial excitations and P-wave states
• Some remarks on $X(6900)$
• Resonance on top of thresholds: the ${\Lambda }_c(2595{)}^{+}$ as an extremely fine-tuned state
• Discovery potential for the LHCb fully-charm tetraquark $X(6900)$ state via $\bar{p}p$ annihilation reaction
• 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
• Pair structure of heavy tetraquark systems

Cited by in corpus (17)

• An updated review of the new hadron states
• Fully-heavy tetraquark spectroscopy in the relativistic quark model
• Tetraquark bound states in constituent quark models: benchmark test calculations
• $S$-wave fully charmed tetraquark resonant states
• Spectroscopy behavior of fully heavy tetraquarks
• Benchmark calculations of fully heavy compact and molecular tetraquark states
• Spectrum of the S-wave fully-heavy tetraquark states
• Going in quest of potential tetraquark interpretations for the newly observed $T_{\psi \psi }$ states in light of the diquark-antidiquark scenarios
• Decay behaviors of the fully-bottom and fully-charm tetraquark states
• Improved understanding of the peaking phenomenon existing in the new di-$J/\psi$ invariant mass spectrum from the CMS Collaboration
• Pseudoscalar charmonium pair interactions via the Pomeron exchange mechanism
• Hadronic molecules with four charm or beauty quarks
• P-wave fully charm and fully bottom tetraquark states
• The $X(6900)$ peak could be a molecular state
• Fully charmed P-wave tetraquark resonant states in the quark model
• Discovering an Unquenched Dynamics Mechanism for Charmonium Scattering
• Finite-temperature effects on the threshold cusps in $\pi \pi$ and $D{\bar{D}}^{\ast }$ scatterings from relativistic heavy-ion collisions