Higher η c(nS) and η b(nS) mesons

The η and η ′ mesons in QCD

Hadronic interaction of η and η ′ mesons with protons Pawe

Hadronic interaction of η and η ′ mesons with protons Acknowledgement Accomplishment of the experiments presented in this treatise was possible only thanks to the joined effort of friends from the COSY-11 group with whom I had the luck to work during many years of my involvement at the Jagellonian University in Poland and the Research Centre Jülich in Germany. I am greatly indebted to all of th...

On the gluon content of the η and η mesons

A phenomenological analysis of radiative V → Pγ and P → V γ decays is performed with the purpose of determining the gluonic content of the η and η′ wave functions. Our results show that within our model there is no evidence for a gluonium contribution in the η, Z2 η = 0.00±0.12, or the η′, Z2 η = 0.04±0.09. In terms of a mixing angle description this corresponds to φP = (41.4±1.3)◦ and |φη′G| =...

Photoproduction of η-mesons from light nuclei

In a series of experiments coherent and quasifree η-photoproduction from light nuclei (He, He, H) was investigated with the TAPS-detector at the Mainz MAMI-accelerator. The experiments were motivated by two different subjects: the determination of the isospin structure of the electromagnetic excitation of the S11(1535) resonance and the study of the η-nucleon and η-nucleus interaction at small ...

Production of η Mesons Near Threshold

It is argued that the strong energy dependence of the p d → 3Heη cross section near threshold is due to a final state interaction between the η meson and the 3He nucleus. The large scattering length that this implies is in accord with optical potential predictions and is evidence for a nearby virtual ‘‘bound’’ state in the η3He system. This model suggests that sharp structures should also be se...