Protoproduction and photodecay experiments at intermediate energy

The ion cooler storage ring, CELSIUS in Uppsala, has now operated several years and provides protons up to an energy of 1360 MeV. The WASA/PROMICE collaboration [1] has studied light-meson production in pp and pd interactions. Especially interesting are recent results on η production in pd collisions near the kinematical threshold where evidence of the N(1535) isobar and of a quasibound ηd system are seen. A wide-angle spectrometer, WASA, is being prepared for studies of rare processes, in particular photodecays and protoproduction of light neutral pseudoscalar mesons.