Related papers: Selecting the physical solution via $\eta$-$\eta'$…
To resolve ambiguities from multiple solutions in experimental measurements, we construct a $\chi^2$ function incorporating constraints such as isospin conservation and amplitude relations. By minimizing the global $\chi^2$, we identify…
It has been controversial whether $\eta_b$ can be discovered in Tevatron Run 2 through the decay $\eta_b\to J/\psi J/\psi$ followed by $J/\psi\to \mu^+\mu^-$. We clear this controversy by an explicit calculation which predicts ${\rm…
We show that the currently available data are consistent with $Y(4230)$ being a $D_1 \bar{D}$ hadronic molecule. By a simultaneous fit to data from $e^+ e^- \rightarrow D^0 D^{* -} \pi^+,\: J/\psi \pi^+ \pi^-,\: J/\psi K^+ K^-,\: h_c \pi^+…
The cross sections of the process $e^{+}e^{-} \to \eta J/\psi$ at center-of-mass energies ($\sqrt{s}$) between 3.81 and 4.60 GeV are measured with high precision by using data samples collected with the BESIII detector operating at the…
Recent BESIII data indicate a significant rate of the process $e^+e^- \to h_c \pi^+ \pi^-$ at the Y(4260) and Y(4360) resonances, implying a substantial breaking of the heavy quark spin symmetry. We consider these resonances within the…
The mixing of $\eta-\eta'$ or $\eta-\eta'-G$ is of a great theoretical interest, because it concerns many aspects of the underlying dynamics and hadronic structure of pseudoscalar mesons and glueball. Determining the mixing parameters by…
Within the framework of the effective Lagrangian approach, we perform a thorough analysis of the $J/\psi \to P\gamma(\gamma^*)$, $J/\psi \to VP$, $V\to P\gamma(\gamma^*)$, $P\to V\gamma(\gamma^*)$ and $P\to\gamma\gamma(\gamma^*)$ processes,…
An approach to the properties of the $\eta$--$\eta'$ system developed to solve the famous $U(1)$ problem is used to calculate the partial widths ratios to $\eta$ and $\eta'$ in the $B^0 \rightarrow J/\Psi \ \eta(\eta',\ \pi^0)$ and $B_s…
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…
We present recent results from the BES experiment on the observation of the Y(2175) in $J/\psi\to \phi f_0(980) \eta$, and $\eta(2225)$ in $J/\psi\to \gamma \phi \phi$, and X(1440) in $J/\psi$ hadronic decays, together with the new…
An introduction to the physics of eta and eta' meson decays is given. A historical account of the discovery of the mesons is presented. It is followed by an overview and classification of the common decay modes and the relevance of the…
In this work, we predict the light hadronic decay channels $Y(4230)\to\Lambda\bar{\Lambda}$ and $\Xi^-\bar{\Xi}^+$ when treating the $Y(4230)$ as a vector charmonium state. By the hadronic loop mechanism, the branching ratios of the…
The hadronic decays eta -> pi pi pi, eta-prime -> pi pi pi and eta-prime -> eta pi pi are investigated within a U(3) chiral unitary approach. Final state interactions are included by deriving the effective s-wave potentials for meson meson…
In this work, we calculate the branching ratios for the $\eta(\eta')\rightarrow\bar{\ell}\ell$ decays, where $\ell = e,\mu$. These processes have tiny rates in the standard model due to spin flip, loop, and electromagnetic suppression, for…
We present a concise review of the vector charmonium state $\psi(4230)$, which was originally labelled as $Y(4260)$ in the literature. As one of the earliest candidates for a QCD exotic states, its interpretation has initiated various ideas…
After explaining necessity of exotic hadrons, we discuss mechanisms which could determine production of the exotic Theta-baryon. A possible important role of resonances (producing the Theta in real or virtual decays) is emphasized for…
A phenomenological analysis on various decay processes is performed using an energy-dependent $\eta-\eta'$ mixing angle scheme. Special attention is given to the radiative couplings between lowest-lying vector and pseudoscalar mesons. The…
Results of many $\psi(2S)$ hadronic decays and the results of $\psi(2S)$ radiative/hadronic transitions from BES collaboration in the past year are presented. Measurement of $\BR(\jpsi\ra K^0_S K^0_L)$ and the preliminary result of…
The cross section for e^+e^- \to \eta J/\psi between \sqrt{s}=3.8 GeV/c^2 and 5.3 GeV/c^2 is measured via initial state radiation using 980 fb^{-1} of data on and around the \Upsilon(nS)(n=1,2,3,4,5) resonances collected with the Belle…
We develop a method to measure the amount of compositeness of a resonance, mostly made as a bound state of two hadrons, by simultaneously measuring the rate of production of the resonance and the mass distribution of the two hadrons close…