Related papers: Gluonic effects in eta- and etaprime-nucleon and n…
We review the theory and phenomenology of the axial U(1) problem with emphasis on the role of gluonic degrees of freedom in eta and eta' production processes, especially the low-energy pN -> pN eta and pN -> pN eta' reactions.
We review the present understanding of etaprime and eta meson physics and these mesons as a probe of gluon dynamics in low-energy QCD. Recent highlights include the production mechanism of eta and etaprime mesons in proton-nucleon…
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,…
We review the theory and phenomenology of the axial U(1) problem with emphasis on the role of gluonic degrees of freedom in the low-energy pp -> pp eta and pp -> pp eta' reactions.
We present results of investigations aiming to determine the hadronic interaction of eta and eta-prime mesons with nucleons. Inferences are based on comparisons of both the differential cross sections and the close-to-threshold excitation…
We argue that eta bound states in nuclei are sensitive to the singlet component in the eta. The bigger the singlet component, the more attraction and the greater the binding. Thus, measurements of eta bound states will yield new information…
A comparison of the close-to-threshold total cross sections for the eta-prime meson production in both the pp --> pp eta-prime and pn --> pn eta-prime reactions should provide insight into the flavour-singlet (perhaps also into gluonium)…
The production of eta and eta-prime mesons in nucleon-nucleon collisions near thresholds is considered within a one-boson exchange model. We show the feasibility of an experimental access to transition formfactors.
Formation of eta-mesic nucleus, a bound state of an eta meson in a nucleus, is reviewed in this paper. Three different theoretical approaches are used to calculate the binding energies and widths of such nuclei. The effect of eta-mesic…
We derive the effective chiral Lagrangian for low energy eta--nucleon and eta'--nucleon interactions and show that gluonic degrees of freedom, via the axial anomaly, induce a contact term in the pp -> pp eta and pp -> pp eta' reactions. We…
The production of eta and eta-prime mesons in elementary nucleon-nucleon collisions has been investigated at the synchrotrons CELSIUS, COSY and SATURNE. The magnitude and energy dependence of the total cross section as well as the…
We discuss the role of gluon dynamics in $\eta'$ physics and in nucleon resonances where excitations of gluonic potentials may also be important. Interesting phenomenology includes a possible narrow near threshold resonance in $\eta'$…
The position and movement of poles of the amplitude for elastic eta-meson scattering off the light nuclei d, t, ^3He, and ^4He are studied. It is found that, within the existing uncertainties for the elementary eta-N interaction, all these…
Back in the mid eighties, a new branch of investigation which was related to the interaction of eta mesons with nuclei came into existence. It started with the theoretical prediction of possible exotic states of eta mesons and nuclei bound…
A comparison of the close-to-threshold total cross section for the eta prime production in pp --> pp eta prime and pn --> pn eta prime reactions constitutes a tool to investigate the eta prime meson structure and the reaction mechanism in…
We give a brief overview of the physics of gluonic degrees of freedom associated with the strong (QCD) axial anomaly. The role of this anomalous glue in the spin structure of the proton and eta'-hadron interactions is discussed.
Eta bound states in nuclei are sensitive to the flavour-singlet component in the eta. The bigger the singlet component, the more attraction and the greater the binding. eta-etaprime mixing plays an important role in understanding the value…
Some aspects of the quasi-free production of mesons in the near threshold region are discussed. A method of data analysis used by WASA/PROMICE Collaboration to extract the excitation function for eta production on neutron target is briefly…
We report on the status of the search for eta-mesic nuclei and the studies of the interaction of the eta meson with nucleons. Recently we have completed the analysis of the new WASA-at-COSY data on the production of the eta meson with…
Due to their short life-time, flavour-neutral mesons cannot be utilized as free secondary beams or targets, and therefore a study of their interaction with nucleons is not possible via direct scattering experiments. This interaction is,…