Photoproduction of $ \eta$ -mesons off neutrons from a deuteron target

A formalism is developed for the partial-wave analysis of data on meson photoproduction off deuterons and applied to photoproduction of $ \eta$ and $ \pi^{0}_{}$ mesons. Different interpretations of a dip-bump structure of the $ \eta$ photoproduction cross-section in the 1670MeV region are presented and discussed. Helicity amplitudes for two low-mass S11 states are determined.