Related papers: The third peak structure in the double $J/\psi$ sp…

Recently, the LHCb Collaboration have updated their analysis of the resonant $J/\psi p$ mass spectrum in the decay $\Lambda_b^0 \to J/\psi p K^-$. In the combined Run~1 and Run~2 LHCb data, three peaks are observed, with the former…

Over the past two decades, numerous exotic hadron states have been discovered, yet their underlying nature remains unclear. It is widely acknowledged that understanding hadron-hadron interactions is essential to unraveling their properties.…

We consider exotic baryons with hidden charm as antiquark-diquark-diquark composite systems. Spin and isospin structure of such exotic states is given and masses are estimated. The data for production of pentaquarks in the reaction…

The near-threshold photoproduction of $J/\psi$ is regarded as one golden process to unveil the nucleon mass structure, pentaquark state involving the charm quarks, and the poorly constrained gluon distribution of the nucleon at large $x$…

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.…

We investigate the $J/\psi \phi$ invariant mass distribution of the $e^+e^-\to \gamma J/\psi\phi$ reaction at a center of mass energy of $\sqrt{s}=4.6$~GeV measured by the BESIII collaboration, who concludes that no significant signals are…

The Ds-Ds*, D*-D*, and Ds*-Ds*, P-wave channels in the energy region of the Y(4260) charmonium structure are studied in a coupled-channel model applied to JPC=1-- c-cbar resonances. The three channels exhibit enhancements that peak at 4.27…

In this work we study the structures near 4.3 GeV in the $J/\psi \phi$ invariant mass spectra in B meson decay process $B^+\to J/\psi \phi K^+$ and two photon fusion process $\gamma\gamma\to J/\psi \phi$. The Y(4274) as a $D_sD_{s0}$…

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…

Using proton-proton collision data at centre-of-mass energies of $\sqrt{s} = 7$, $8$ and $13\mathrm{\,TeV}$ recorded by the LHCb experiment at the Large Hadron Collider, corresponding to an integrated luminosity of $9\mathrm{\,fb}^{-1}$,…

Very recently, the LHCb Collaboration reported the observation of several enhancements in the invariant mass spectrum of a $J/\psi$ pair between 6.2 and 7.4 GeV. In this work, we propose the dynamical mechanism to mimic the experimental…

Partial wave analysis is performed, with effective potentials as dynamical inputs, to scrutinize the recent LHCb data on the di-$J/\psi$ invariant mass spectrum. Coupled-channel effects are incorporated in the production amplitude via final…

A search is reported for near-threshold structures in the J/$\psi$J/$\psi$ invariant mass spectrum produced in proton-proton collisions at $\sqrt{s}$ = 13 TeV from data collected by the CMS experiment, corresponding to an integrated…

Recent high-precision $e^+e^-\to c\bar{c}$ data from the BESIII and Belle are highly useful to understand vector charmonium ($\psi$) pole structures and puzzling lineshapes due to the exotic hadron candidates $Y$. We thus perform a global…

A search is reported for structures near the $J/\psi$ $J/\psi$ mass threshold using a dataset of proton-proton collisions at $\sqrt{s} \: =13 \: \mathrm{TeV} $ recorded with the CMS detector at the LHC, corresponding to an integrated…

The double-charmonium scattering states such as $J/\psi J/\psi$, $\eta_cJ/\psi$, and $\eta_c\eta_c$ are investigated by a simplified quark cluster model. It is found that the quark Pauli-principle over the $c\bar c c\bar c$ system causes a…

Based on 7.8 million J/\psi events collected at BEPC, the events for J/\psi \to p\bar{p}\pi^0 and p\bar{p}\eta have been selected and reconstructed. Clear peaks are observed around 1480 MeV in p\pi^0 (\bar{p}\pi^0) invariant mass spectrum…

With a sample of 225.3 million $J/\psi$ events taken with the BESIII detector, the decay $J/\psi\rightarrow \gamma 3(\pi^+\pi^-)$ is analyzed. A structure at 1.84 GeV/c$^2$ is observed in the $3(\pi^+\pi^-)$ invariant mass spectrum with a…

Two near-threshold peaking structures with spin-parities $J^{\mathrm{PC} }=0^{++}$ were recently discovered by the LHCb Collaboration in the $ D_{s}^{+}D_{s}^{-}$ invariant mass distribution of the decay $ B^{+}\rightarrow…

Using 58 million $J/\psi$ decays, we have investigated the $p \bar{p}$ invariant mass spectrum in the radiative decay $J/\psi \to \gamma p \bar{p}$ and observe a prominent structure with mass near $2m_p$. Fitting with an S-wave…