Related papers: Partial wave effects in the heavy quarkonium radia…
As double heavy quarkonia, charmonium and bottomonium are generally considered to have small relativistic corrections and can be treated using nonrelativistic models. However, this is not always the case. In this paper, we employ the…
BES data on $J/\psi \to \gamma (\pi^{+} \pi^{-} \pi^{+} \pi^{-})$ have been analyzed into partial waves. We fit with resonances having $J^{PC}=2^{++}$ at 1275 MeV, $0^{++}$ at 1500 MeV, $2^{++}$ at 1565 MeV, $0^{++}$ at 1740 MeV, $2^{++}$…
In the framework of the spectral integral equation, we consider the $b\bar b$ states and their radiative transitions. We reconstruct the $b\bar b$ interaction on the basis of data for the levels of the bottomonium states with…
We argue that the photon spectra in radiative decays of various heavy quarkonium states provide important information on their nature. If two of these states are in the strong coupling regime, we are able to produce a parameter-free model…
The experimental status of stable bound states made out of heavy quarks is reviewed. The need for a way to deal with the non-perturbative transitions involved calls for precision measurements on one hand, and for discovery of as yet…
We construct a formalism which describes the resonances decaying into four pseudoscalar meson final states. This method is fully covariant and can be directly applied for the partial-wave analysis of high statistical data. Two topologies of…
The recent observation and measurement of the decay $Z_c(3900) \to \rho \eta_c$ provides the data on the relative strength of the pion and $\rho$ coupling in the corresponding transitions between exotic resonances and pure heavy quarkonium.…
The mixing of $S-D$ partial waves for the heavy meson pairs in the decays $\Upsilon(5S) \to [B^* \bar B+ {\rm c.c.}] \pi$ and $\Upsilon(5S) \to B^* \bar B^* \pi$ is considered. It is argued that this mixing, enhanced by the heavy meson…
This paper proposes a novel mechanism based on the instantaneous Bethe-Salpeter (Salpeter) equation for investigating wave function mixing in vector mesons such as $\psi(3770)$. Conventional theories typically treat $\psi(3770)$ as a…
We calculate the transition between a quarkonium state and an unbound heavy quark-antiquark pair through gluo-dissociation and inelastic parton scattering using a partonic picture that interpolates between the formal limits based on…
Radiative decays of heavy baryons are analyzed within the Heavy Quark Symmetry (HQS). It is shown that employing the light-diquark symmetries, the number of electromagnetic couplings among S-wave and P-wave states as well as those between…
The decay widths of S-wave quarkonia ($\etc,\etb\to \gg{~~and~~} \J,\U\to\ee$) are calculated on the basis of a quasipotential approach. The nontrivial dependence on relative quark motion of decay amplitude is taken into consideration via…
In this paper we study the weak decays of $J/\psi$ and $\Upsilon(1S)$. Using the Bethe-Salpeter method, we calculate the hadronic transition amplitude and give the form factors. We find that two new form factors $h_1$ and $h_2$, which do…
The processes of P-wave Quarkonium exclusive decays to two mesons are investigated, in which the final state vector mesons with various polarizations are considered separately. In the calculation, the initial heavy quarkonia are treated in…
We examine the electronic width ratios of Upsilon resonances below the BBbar threshold by means of an effective (Cornell-type) QCD potential incorporating 1/m_b corrections obtained from a prior fit to the bottomonium spectrum. From our…
The abundant $\psi'$ events have been collected at the Beijing Electron Positron Collider-II (BEPCII) that could undoubtedly provide us with a great opportunity to study the more attractive charmonium decays. As has been noticed before, in…
An explanation of the difference in the values of the apparent $f/d$ ratios for the S- and P- wave amplitudes of nonleptonic hyperon decays is proposed. The argument is formulated in the framework of the standard pole model with…
In the heavy quarkonium decay process $ V \to ggg $ ($ V=J/\psi, \Upsilon $), making a definite prediction including relativistic corrections has so far remained a significant challenge. In this work, we study this decay process by taking…
Semileptonic decays of heavy baryons consisting of one heavy (Q=b,c) and two light (q=u,d,s) quarks are considered in the heavy-quark--light-diquark approximation. The relativistic quasipotential equation is used for obtaining masses and…
Using $5.8 \times 10^7 J/\psi$ events collected in the BESII detector, the radiative decay $J/\psi \to \gamma \phi \phi \to \gamma K^+ K^- K^0_S K^0_L$ is studied. The $\phi\phi$ invariant mass distribution exhibits a near-threshold…