Related papers: Shedding light on charmonium
The $P$-wave charmonium decays $h_{c}\rightarrow\gamma\eta^{(\prime)}$ are revisited by taking into account relativistic corrections. The decay amplitudes are derived in the Bethe-Salpeter formalism, in which the involved one-loop integrals…
The study of electron-positron collisions at center-of-mass energies corresponding to charmonium production has reached new levels of sensitivity thanks to experiments by the BES and CLEO Collaborations. Final states $\gamma P$, where $P$…
In the precedent paper of the authors (hep-ph/0510410), the $b\bar b$ states were treated in the framework of the spectral integral equation, together with simultaneous calculations of radiative decays of the considered bottomonia. In the…
Mass spectrum of charmonium is computed in the framework of potential non-relativistic quantum chromodynamics. \textit{O}$(1/m)$ and \textit{O}$(1/m^2)$ relativistic corrections to the Cornell potential and spin-dependent potential have…
The form factors for the radiative transitions between charmonium mesons are investigated. We employ an anisotropic lattice using a Wilson gauge action, and domain-wall fermion action. We extrapolate the form factors to $Q^2 = 0$,…
We calculate the single-quark electromagnetic form factors of a broad subset of charmonium, including $\eta_c(1S)$, $\eta_c(2S)$, $\chi_{c0}(1P)$, $\chi_{c0}(2P)$, $J/\psi(1S)$, $J/\psi(2S)$, $\chi_{c1}(1P)$, $\chi_{c1}(2P)$, $h_c(1P)$,…
We calculate the amplitudes and branching fractions of $\chi_{cJ}$, $h_c$, $J/\psi$, and $\psi(2S)$ radiative decays in the framework of the covariant confined quark model. First, we explicitly show that all calculated amplitudes are gauge…
Charmonia spectral functions at finite temperature are studied using QCD sum rules in combination with the maximum entropy method. This approach enables us to directly obtain the spectral function from the sum rules, without having to…
A study of $B^+ \rightarrow J/\psi \eta K^+$ decays, followed by $J/\psi \rightarrow \mu^+ \mu^-$ and $\eta \rightarrow \gamma \gamma$, is performed using a dataset collected with the LHCb detector in proton-proton collisions at…
I review possible resolution of the $J/\psi (\psi^{\prime}) \to \rho-\pi$ puzzle based on two inputs: the relative phase between the one- photon and the gluonic decay amplitudes, and a possible hadronic excess in the inclusive…
Based on $\psi(3686)$ decays of 106 million, the 1.31 billion J/psi events and a data sample of $\psi(3770)$ with $2.9~fb^{-1}$ integrated luminosity, many analyses are performed. Exclusively baryonic decays of the $\psi(3770)$, the…
The charmonium transitions from the $\chi_{cJ}$ states to $\eta_c$ with emission of one or two pions are considered. It is shown that the only processes of such type arising in the leading order in the QCD multipole expansion are the decays…
In this work, we investigate the form factors of $B_c$ decays into $J/\Psi, \psi(2S,3S)$, $\eta_c, \eta_c(2S,3S), \chi_{c0}, \chi_{c1}, h_c$ and $X(3872)$ mesons in the covariant light-front quark model (CLFQM). For the purpose of the…
The charmonium system is studied in a Salpeter model with a vector plus scalar potential. We use a kinematical formalism based on the one developed by Suttorp, and present general eigenvalue equations and expressions for decay observables…
In this work a comprehensive analysis of the mass spectrum and decay properties of charmonium states within a relativistic framework is carried out. The present experimental status of charmonium states is reviewed. Utilizing a screened…
We study the semileptonic decay of the $B_c (0^-)$ to charmonia through the bottom-to-charm-quark electroweak current in the framework of basis light-front quantization. Explicitly, we calculate the weak transition form factors for…
We make the first calculation in lattice QCD of two-photon decays of mesons. Working in the charmonium sector, using the LSZ reduction to relate a photon to a sum of hadronic vector eigenstates, we compute form-factors in both the…
Massless perturbative QCD forbids, at leading order, the exclusive annihilation of proton-antiproton into some charmonium states, which, however, have been observed in the $p\bar p$ channel, indicating the significance of higher order and…
The presented paper is devoted to theoretical analysis of charmonium mesons $\eta_c$, $J/\psi$, $\chi_{c0,1,2}$, and $h_c$ production in exclusive radiative $Z$ boson decays in the frameworks of Nonrelativistic Chromodynamic and amplitude…
In the framework of a relativistic quark model constructed in an infinite momentum frame, corrections of the order of $v^{2}/c^{2}$ are obtained in the formulas which express amplitudes of the transitions $\psi(\psi') \to…