Eta Production In Proton-Proton Collisions At 72 Mev Excess Energy

The production of eta mesons at an excess energy of 72 MeV has been studied in the reaction pp -> pp(eta)gamma gamma. It is shown that a simple model with Pp. final states included reproduces observed differential distributions better than the same model restricted to Ss, Sd and Ds final states. The strong influence of the Pp states could be taken as an indication of rho dominance within an one boson exchange model for the excitation of N*(1535).