Related papers: Meson-Photon Transition Form Factors in the Charmo…
A detailed analysis is performed of transverse momentum spectra of several identified hadrons in high energy collisions within the framework of the statistical model of hadronisation. The effect of the decay chain following hadron…
The advent of back-scattered laser beams for electron-positron colliders will allow detailed studies of a large array of high energy photon-photon and photon-electron collision processes with polarized beams. These include tests of…
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…
Photoproduction cross sections are reported for the reaction $\gamma p\to p\eta$ using energy-tagged photons and the CLAS spectrometer at Jefferson Laboratory. The $\eta$ mesons are detected in their dominant charged decay mode, $\eta\to…
The ALICE Collaboration at the LHC has measured the J/$\psi$ and $\psi^{'}$ photoproduction at mid-rapidity in ultra-peripheral Pb-Pb collisions at $\sqrt{s_{\rm NN}}=2.76$ TeV. The charmonium is identified via its leptonic decay for events…
An analysis of incoherent photoproduction of $\eta$ mesons off the deuteron for photon energies from threshold to 800 MeV is presented. The dominant contribution, the $\gamma$N-$\eta$N amplitude, is described within an isobar model. Effects…
The energy spectrum for high energy $\gamma$-rays ($E_\gamma \geq 10$ MeV) from the process $pp \to \gamma \gamma X$ emitted at $90^0$ in the laboratory frame has been measured at 216 MeV. The resulting photon energy spectrum extracted from…
The BESIII Collaboration has recently reported two measurements of the two-photon decay width of the $\eta_c$ meson. The 2024 result is significantly larger than most theoretical and empirical expectations, while a subsequent measurement…
The CLEO-c Experiment has made several recent contributions to the study of charmonium decays. This review briefly outlines the CLEO-c analyses of charmonium that were completed or made public during 2010. Special attention is given to the…
Recent data on charmonium production in B-meson decays suggest that charmonium hybrid mesons with mass ~4 GeV may be produced in B-decay via c\bar{c} colour octet operators. Some of these states are likely to be narrow with clean signatures…
The h_c(1P1) state of charmonium has been observed in the reaction \psi(2S) -> \pi0 h_c -> (\gamma\gamma)(\gamma\eta_c) using 3.08 million \psi(2S) decays recorded in the CLEO detector. Data have been analyzed both for the inclusive…
The reaction $ pp \to pp \eta \to pp \gamma e^+ e^-$ is discussed within a covariant effective meson-nucleon theory. The model is adjusted to data of the subreaction $pp \to pp \eta$. Our focus is on di-electrons from Dalitz decays of…
We study charmonium production in proton-nucleus ($p$-A) collisions focusing on final-state effects caused by the formation of an expanding medium. Toward this end, we utilize a rate equation approach within a fireball model as previously…
The measurement of charmonium states produced in proton-neon ($p$Ne) collisions by the LHCb experiment in its fixed-target configuration is presented. The production of $J/\psi$ and $\psi(2S)$ mesons is studied with a beam of 2.5 TeV…
We study charmonium production at high-energy colliders (Tevatron, HERA, and LEP2) in the framework of the k_T-factorization approach and the factorization formalism of non-relativistic quantum chromodynamics at leading order in the…
The photon-photon interaction in ultra-relativistic heavy-ion collision is a source of the $(e^+,e^-)$ pairs. The photon-photon fusion leads the lepton creation in the broad configuration space around "collision" point. Those created close…
Differential cross sections at $t=t_{\text{min}}$ and decay asymmetries for the $\gamma p\rightarrow\phi p$ reaction have been measured using linearly polarized photons in the range 1.5 to 2.9 GeV. These cross sections were used to…
The differential cross sections for the production of photons in Z to mu+ mu- gamma decays are presented as a function of the transverse energy of the photon and its separation from the nearest muon. The data for these measurements were…
The decays of narrow light vector mesons into pseudoscalar mesons and dileptons are calculated to leading order in a recently proposed scheme which treats pseudoscalar and vector mesons on equal footing. Since all required parameters have…
In this article, we review the status of the charmonium production in low energy fixed target proton-nucleus (p-A) and nucleus-nucleus (A-A) collisions as measured by different experimental collaborations at CERN-SPS, Fermilab and HERA…