Paper detail

The role of pion exchange in $η$ meson photo production on the deuteron

Incoherent $η$ photoproduction on the deuteron is studied with the main emphasis on the role of final state interactions. In addition to the previously studied mechanisms of $NN$ and $ηN$ rescatterings, the role of an intermediate pion exchange is considered in detail, where first a pion is photoproduced on one nucleon and then rescatters into an $η$ meson on the other, the spectator nucleon. It is found, that the role of this pion mediated contribution is comparable in size to that of $ηN$ rescattering. Results for total and semi-inclusive differential cross sections and associated polarization observables are presented. In particular polarization observables show a significant sensititvity to final state interactions.