Related papers: Evidence for a J/psi-ppbar Pauli Strong Coupling ?
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…
The QCD mechanisms underlying the exclusive strong decays and hadronic production amplitudes of charmonium remain poorly understood, despite decades of study and an increasingly detaled body of experimental information. One set of hadronic…
The production of charmonia is investigated for heavy-ion collisions from SPS to RHIC energies. Our approach incorporates two sources of $J/\Psi$ yield: (i) a direct contribution arising from early (hard) parton-parton collisions, subject…
In e^+e^- annihilation at \sqrt{s}=10.6 GeV Belle Collaboration found, that J/psi mesons are predominantly produced in association with an extra \bar{c}c pair. The possible mechanisms of J/psi production are discussed and the probability of…
A search is performed for the central exclusive production of pairs of charmonia produced in proton-proton collisions. Using data corresponding to an integrated luminosity of $3{\rm\ fb}^{-1}$ collected at centre-of-mass energies of 7 and 8…
We study $J/\psi$ suppression in Pb+Pb collisions at CERN-SPS energies in hadronic matter with energy- and temperature-dependent charmonium dissociation cross sections calculated in the quark-interchange model of Barnes and Swanson. We find…
In this invited talk I discuss two recent applications of charmonium (Psi) decays to N Nbar m final states, where N is a nucleon and m is a light meson. There are several motivations for studying these decays: 1) They are useful for the…
The power suppressed amplitude which describes the Pauli ($\sigma^{\mu\nu}$) coupling in the $J/\psi\to p\bar p$ decay is calculated within the effective field theory framework. It is shown that at the leading-order approximation this…
High-precision $e^+e^-\to c\bar{c}$ data (20 final states) from the BESIII and Belle in $\sqrt{s}=3.75-4.7$ GeV are analyzed with a semi three-body unitary coupled-channel model. Vector charmonium poles are extracted from the amplitudes…
Both charm and bottom quarks form nonrelativistic bound states analogous to positronium. The J/psi and psi(2S) charmonium states and the first three Upsilon(nS) bottomonium states, all spin-triplet S-wave quarkonium states below…
The double-charmonium scattering states such as $J/\psi J/\psi$, $\eta_cJ/\psi$, and $\eta_c\eta_c$ are investigated by a simplified quark cluster model. It is found that the quark Pauli-principle over the $c\bar c c\bar c$ system causes a…
The cross sections for the charmonium production processes p pbar -> m Psi, where m is a light meson and Psi is a charmonium state, are of great interest for the planned p-pbar experiment PANDA. In this paper we estimate these cross…
We report the observation of prompt J/psi via double ccbar production from the e+e- continuum. In this process one ccbar pair fragments into a J/psi meson while the remaining pair either produces a bound charmonium state or fragments into…
Within a perturbative approach we investigate decays of charmonium states into baryon-antibaryon pairs. Using a recently proposed wave function for the nucleon and suitable generalizations of it to the hyperons and decouplet baryons, we…
The production of charmonia in relativistic heavy-ion collisions is formulated within the framework of a quantum kinetic theory simultaneously accounting for breakup and recombination processes. The survival probability of J/Psi mesons is…
Recently, the BESIII collaboration performed a precise measurement of the $e^+e^-\to \eta J/\psi$ cross section. It is puzzling that the resonance parameters of the reported $Y(4230)$ show a substantial divergence from the previously…
In this paper we summarize our recent results for low energy associated charmonium production cross sections, using 1) crossing symmetry, and 2) an explicit hadronic model. These predictions are of relevance to the planned charmonium and…
The J/\Psi(1S) and \Psi'(2S) production near threshold in antiproton-nucleus reactions is calculated on the basis of the Glauber model. The model takes into account the antiproton (pre)absorption, proton Fermi motion, and charmonium…
The study of the charmonium (cbar c) system is a powerful tool to understand the strong interaction. In pbar p annihilations studied with PANDA, the mass and width of the charmonium state, such as h_c, will be measured with an excellent…
Studying the production of J/$\psi$ (bound state of charm and anti-charm quark) in proton-proton collisions gives an opportunity to test quantum chromodynamics (QCD) calculations, as the production of J/$\psi$ involves both perturbative and…