Related papers: Some remarks on $X(6900)$
The analyses of the LHCb data on $X(6900)$ found in di-$J/\psi$ and $J/\psi \psi(3686)$ systems are performed using a momentum-dependent {Flatt\'{e}}-like parameterization. The use of the pole counting rule and spectral density function sum…
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 near-threshold enhancement in the $D_s^+ D_s^-$ system, dubbed as $X(3960)$, is observed by the LHCb collaboration recently. A combined analysis on $\chi_{c0}(3930)~(\to D^+ D^-)$, $X(3960)~(\to D_s^+ D_s^-)$, and $X(3915)~(\to…
The pole counting rule is a powerful and model-independent method to distinguish a confining state from a hadronic molecule. It has been applied to the explorations of $X(6900)$, $X_1(2900)$ as well as $Z_c(3900)$, $X(3872)$, $X(4660)$,…
Recently, the LHCb Collaboration reported pronounced structures in the invariant mass spectrum of $J/\psi$-pairs produced in proton-proton collisions at the Large Hadron Collider. In this Letter, we argue that the data can be very well…
In this paper, we study the resonant state $X(6900)$. The scattering amplitudes of coupled channels, $J/\psi J/\psi$-$J/\psi \psi(2S)$-$J/\psi \psi(3770)$, are constructed with the interaction of four vector mesons described by effective…
Recent re-analyses of the di-$J/\Psi$ invariant mass spectra reveal a state near the di-$J/\Psi$ threshold, referred to as the $X(6200)$. Yet the nature of this near-threshold pole--whether it is a resonant, bound, or virtual state--remains…
The 2020 announcement by LHCb of a narrow structure $X(6900)$ in the di-$J/\psi$ spectrum -- a potential $c\bar c c\bar c$ state -- has opened a new era in hadronic spectroscopy. In this talk, we briefly survey theory works preceding this…
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.…
The analyses of the LHCb data on X(2900) in the D^- K^+ spectrum are performed. Both dynamically generated and explicitly introduced X_1(2900) are considered. The results show that both these two approaches support the interpretation of…
Inspired by the observation of the $P_{cs} (4459)$ state by LHCb recently, we reexamine the results of the interaction of the $J/\psi \Lambda$ channel with its coupled channels, exploiting the coupled channel unitary approach combined with…
In this work, the $S$- and $P$-wave $\bar{D}^\ast K^\ast$ interactions are studied in a coupled-channel formalism to understand the recently observed $X_0(2900)$ and $X_1(2900)$ at LHCb. The experimental event distributions can be well…
We report stronger evidence for the $X(7200)$ state and markedly improved measurements of the $X(6900)$ resonance parameters based on a combined analysis of the di-$J/\psi$ mass spectrum using published data from LHCb, ATLAS, and CMS.…
The LHCb Collaboration recently observed new structures in the invariant mass spectrum of $J/\psi J/\psi$ meson pairs produced in proton-proton collisions, including a narrow peak around $6.2$ GeV. This study investigates the thermal…
Within the framework of the local hidden gauge approach, we have studied the near-threshold interaction of the $D^* \bar{D}^*$ channel with quantum numbers $I(J^{PC}) = 0(0^{++})$, $0(2^{++})$, $1(0^{++})$, and $1(2^{++})$, respectively.…
Stimulated by the measurement of the $J\psi\phi$ decay model of $Y(4274)$ by the LHCb Collaboration, we consider a possible interpretation of this state as a hadron molecular-a bound state of $D_s$ and $\bar{D}_{s0}(2317)$ mesons. Using…
In this letter, we perform partial wave decomposition on coupled-channel scattering amplitudes, $J/\psi J/\psi$-$J/\psi \psi(2S)$-$J/\psi \psi(3770)$, to study the resonance appears in these processes. Effective Lagrangians are used to…
Motivated by recent experimental evidence for apparent $cc\bar c \bar c$ states at LHCb, CMS and ATLAS, we consider how the mass spectrum and decays of such states can be used to discriminate among their possible theoretical…
The strong and electromagnetic decays of $X(4350)$ with quantum numbers $J^P =0^{++}$ and $2^{++}$ have been studied by using the effective Lagrangian approach. The coupling constant between $X(4350)$ and $D_s^{\ast}D_{s0}^{\ast}$ is…
Very recently, the CMS Collaboration reported a peaking phenomenon existing in the di-$J/\psi$ invariant mass spectrum from $pp$ collision, by which the $X(6900)$ structure announced by the LHCb Collaboration was confirmed, but also more…