Related papers: $\eta$ Meson Physics at Gem

For the forward going proton and $\eta$ meson, the coherent $\eta$ meson production in the $(p,p^\prime)$ reaction on the spin-isospin saturated nucleus occurs only due to the $\eta$ meson exchange interaction between the beam proton and…

We shortly discuss results on the isospin dependence of the eta-prime production cross section in nucleon-nucleon collisions, results of comparative analysis of the invariant mass distributions for the pp-->pp eta-prime and pp-->pp eta…

We compare and review the theoretical predictions for the $\bar{K}N$ and $\eta N$ elastic amplitudes where sizable variations are found among the considered approaches, especially at subthreshold energies relevant for studies of kaonic…

The results of mixing angle measurement for $\eta'$, $\eta$ mesons generated in charge exchange reactions with $\pi^{-}$ and $K^{-}$ beams are preseneted. When the $\eta'$, $\eta$ mesons are described in nonstrange(NS)--strange(S) quark…

By means of the COSY-11 detection system, using a stochastically cooled proton beam of the cooler synchrotron COSY and a hydrogen cluster target, we have performed a high statistics measurement of the pp --> pp eta reaction at an excess…

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…

A combined analysis of the existing data on the reactions $\gamma p \to p \eta^\prime $ and $pp \to pp\eta^\prime $, based on a relativistic meson exchange model of hadronic interactions, is presented.

We discuss the eta and eta prime photo- and electroproduction as a way to probe the nucleon resonance structure.

The COSY accelerator in J\"{u}lich is presented together with its internal and external detectors. The physics program performed recently is discussed with emphasis on strangeness physics and precision experiments.

The experimental data on the production of $K^-$-mesons in pp-collisions are analyzed and a method of the unified description of these data in a broad energy range for primary protons is proposed. The $K^-$-mesons production in…

Decays of the neutral and long-lived $\eta$ and $\eta'$ mesons provide a unique, flavor-conserving laboratory to test low-energy Quantum Chromodynamics and search for new physics beyond the Standard Model. They have drawn world-wide…

We summarise recent progress in theory and experiment towards understanding etaprime meson interactions with nucleons and nuclei. Highlights include the production mechanism of etaprime mesons in proton-proton collisions close to threshold,…

At the HERA collider the experiments H1 and ZEUS have studied the exclusive production of vector mesons over a wide kinematical range. A selection of recent measurements of the cross sections has been presented at Moriond QCD 2003.

Using the Crystal Barrel(CB)/TAPS detector system at the ELSA accelerator facility in Bonn the \eta' photoproduction off nuclei (C, Ca, Nb and Pb) was studied via the hadronic decay channel \eta' -> \pi^0\pi^0\eta . Recent results on the…

We investigate the pp --> pp eta and pn --> pn eta reactions within an effective Lagrangian model for laboratory kinetic energies ranging from very close to eta meson production threshold to about 10 GeV. Production amplitudes include…

The excitation function for the $pd\rightarrow$ $d p \pi^{0}$ reaction has been measured by WASA-at-COSY experiment with the aim of searching for $^{3}\hspace{-0.03cm}\mbox{He}$-$\eta$ mesic nuclei. The measurement in the vicinity of $\eta$…

Since the eta meson is a short-lived neutral particle, it is not possible to investigate its structure via classical methods of particle scattering. To learn about its quark wave function, one studies those decay processes of this meson in…

We argue that the electroproduction of exotic particles is a useful tool for study of their partonic structure. In the case of hybrid mesons, the magnitude of their cross sections shows that they are accessible for measurements in existing…

The production of $\eta^\prime$ mesons in coincidence with forward-going protons has been studied in photon-induced reactions on $^{12}$C and on a liquid hydrogen (LH$_2$) target for incoming photon energies of 1.3-2.6 GeV at the electron…

Photoproduction of $\eta$ mesons from neutrons} \abstract{Results from measurements of the photoproduction of $\eta$ mesons from quasifree protons and neutrons are summarized. The experiments were performed with the CBELSA/TAPS detector at…