The last decade has witnessed great experimental progress that has led to measurements of
near-threshold cross sections—polarized as well as unpolarized—of high accuracy for …

A review of the present understanding of η′ and η meson physics and these mesons as a
probe of gluon dynamics in low-energy QCD is presented. Recent highlights include the …

We investigate the nature of the near-threshold enhancement in the pp¯ invariant-mass
spectrum of the reaction J/Ψ→ γ pp¯ reported recently by the BES Collaboration. Using the …

The production of η and η′ mesons in photon-and hadron-induced reactions on free and
quasi-free nucleons and on nuclei is reviewed. The extensive database on γ N→ η N, for …

A high statistics measurement of the pp→ pp η reaction at an excess energy of Q= 15.5 MeV
has been performed at the internal beam facility COSY-11. The stochastically cooled proton …

Back in the mid-1980s, a new branch of investigation related to the interaction of eta mesons
with nuclei came into existence. It started with the theoretical prediction of possible exotic …

The production of η′ mesons in photon-and hadron-induced reactions has been revisited
in view of the recent additions of high-precision data to the world data base. Based on an …

A dispersion integral is derived that allows one to relate directly (spin-dependent) Λ N
invariant mass spectra, measured in a large-momentum transfer reaction such as pp→ K+ p …

Taking advantage of both the high mass resolution of the COSY-11 detector and the high
energy resolution of the low-emittance proton beam of the cooler synchrotron COSY, we …

The production of η′ mesons in the reactions γ p→ p η′ and pp→ pp η′ is described
consistently within a relativistic meson exchange model of hadronic interactions. The …