Related papers: Study of the $Y(4660)$ from a light-quark perspect…
Recently, the Belle Collaboration has updated the analysis of the cross sections for the processes $e^+ e^- \to \Upsilon(nS)\, \pi^+ \pi^-$ ($n = 1,\, 2,\, 3$) in the $e^+ e^-$ center-of-mass energy range from 10.52 to 11.02~GeV. A new…
The isospin violation process $Y(4260) \to J/\psi \eta \pi^{0}$ is studied assuming that $Y(4260)$ is a $D_{1} \bar{D}+c.c.$ hadronic molecule. In association with the production of the $Z_c(3900)$, which is treated as a $D…
Studying the hidden-charm dipion decays of the charmoniumlike state Y(4360), we show that there exist charged charmoniumlike structures near $D\bar{D}^*$ and $D^*\bar{D}^*$ thresholds in the $J/\psi\pi^+$, $\psi(2S)\pi^+$ and $h_c(1P)\pi^+$…
We investigate the structure $X(4630)$ discovered by the LHCb collaboration in the process $B^{+}\rightarrow J/\psi \phi K^{+}$ as a resonance in the $ J/\psi \phi $ mass distribution. We explore this resonance as a diquark-antidiquark…
It is shown that the basic shape of dipion and $K\overline{K}$ mass spectra in decays $J/\psi\to\phi(\pi\pi,K\overline{K})$, $\psi(2S)\to J/\psi\,\pi\pi$, $Y(4260)\to J/\phi~\pi\pi$ and in the two-pion transitions of bottomonia states are…
We calculate the light-cone wavefunctions of the pion by solving the meson boundstate problem in a coarse transverse lattice gauge theory using DLCQ. A large-N_c approximation is made and the light-cone Hamiltonian expanded in massive…
A combined fit is performed to the BaBar and Belle measurements of the e+e- to pi+pi-psi(2S) cross sections for center-of-mass energy between threshold and 5.5 GeV. The resonant parameters of the Y(4360) and Y(4660) are determined. The mass…
Via the Initial Single Pion Emission (ISPE) mechanism, we study the $\phi(1020)\pi^{+}$ invariant mass spectrum distribution of $Y(2175) \to \phi(1020)\pi^{+} \pi^{-}$. Our calculation indicates there exist a sharp peak structure…
Using the QCD sum rules we test if the charmonium-like structure Y(4260), observed in the $J/\psi\pi\pi$ invariant mass spectrum, can be described with a $J/\psi f_0(980)$ molecular current with $J^{PC}=1^{--}$. We consider the…
We study the process $e^+e^-\to J/\psi\pi^{+}\pi^{-}$ with initial-state-radiation events produced at the PEP-II asymmetric-energy collider. The data were recorded with the BaBar detector at center-of-mass energies 10.58 and 10.54 GeV, and…
The invariant mass spectrum of the $e^{+}e^{-}$ and $\mu ^{+}\mu ^{-}$ pairs from decays of light unflavored mesons with masses below the $\phi (1020)$-meson mass to final states containing along with a dilepton pair one photon, one meson,…
The charmoniumlike state $Y(4260)$ is described as predominantly a $D_1 \bar{D}$ molecule in a coupled-channel quark model [Phys.\,Rev.\,D\,\textbf{96},\,114022\,(2017)]. The heavy quark spin symmetry (HQSS) thus implies the possible…
In the present work, we propose $Y(4140)$ as the $\chi_{c1}(3P)$ state by studying the $\chi_{c1} \pi^+ \pi^-$ invariant mass spectrum of the $B\to K \chi_{c1} \pi^+ \pi^-$ process. In the $D\bar{D}$ invariant mass spectrum of the $B\to K…
We theoretically study how the peculiar properties of the vacuum state of an ultra-strongly coupled system can affect basic light-matter interaction processes. In this unconventional electromagnetic environment, an additional emitter no…
The mass of $P$-wave $cs$-scalar-diquark $\bar{c}\bar{s}$-scalar-antidiquark state is computed in the framework of QCD sum rules. The result $4.69\pm0.36{GeV}$ is in good agreement with the experimental value of Y(4660) but higher than…
By assuming that $Y(4260)$ is a $D_1\bar D$ molecular state, we investigate some hidden-charm and charmed pair decay channels of $Y(4260)$ via intermediate $D_1\bar D$ meson loops with an effective Lagrangian approach. Through investigating…
We propose that the broad $1^{--}$ resonance structure recently discovered by BES in $J/\psi\to K^{+}K^{-}\pi^{0}$ is the P-wave excitation of a diquark-antidiquark bound state. This interpretation implies that there exists a negative…
The internal structure of light scalar state $a_0(1450)$ has not been definitively determined, it may consist of multiple possible states. Among them, it has the possibility of being regarded as a diquark state. Based on this possibility,…
We systematically study the mass spectrum and strong decays of the S-wave $\bar c\bar s q q$ states in the compact tetraquark scenario with the quark model. The key ingredients of the model are the Coulomb, the linear confinement, and the…
QCD Laplace sum-rules are used to examine the constituent mass spectrum of $J^P\in\{0^+,1^+\}$ heavy-light [Qq] diquarks with $Q\in\{c,b\}$ and $q\in\{u,d,s\}$. As in previous sum-rule studies, the negative parity $J^P\in\{0^-, 1^-\}$ [Qq]…