Photoproduction of $\eta$-mesons off protons and deuterons

Abstract

An effective field theory with hadrons and photons is constructed, where the hadronic parameters are determined by fitting elastic $\pi$N scattering data. The predicted pion-induced $\eta$-production on the nucleon agrees well with the data. The hadronic model is then used to describe the final-state interaction in photoinduced processes. We present a consistent description of pion photoproduction in the E$_0^+$-channel and of the total cross sections for photoinduced $\eta$-production on the proton as well as on the deuteron.