Coulomb-scattering and eta - eta-prime mixing angle

The fascinating physics underlying eta and eta-prime mesons can be studied theoretically and experimentally in various contexts. In this presentation we want to turn our attention to two important uncorrelated aspects of this vivid research field which provide yet unexpected challenges or surprises. First we discuss open questions in the theoretical treatment of Coulomb-interaction in the context of reaction processes like p p --> p p eta. Then we review eta - eta-prime and sigma(600) - f_0(980) mixing in the U(3) x U(3) Linear Sigma Model and extract information on eta - eta-prime mixing and the K*0(800) resonance from meson-meson scattering.