We present a combined analysis of the new eta photoproduction data for total and differential cross sections, target asymmetry and photon asymmetry. Using basic assumptions, this allows a model-independent extraction of the $E_{ 2-}$ and $M_{ 2-}$ multipoles as well as resonance parameters of the $D_{ 13}(1520)$ state. At higher energy, we show that the photon asymmetry is extremely sensitive to small multipoles that are excited by photons in the helicity 3/2 state. These could be, e.g., the $F_{ 15}(1680)$, the $F_{ 17}(1990)$, or the $G_{ 17}(2190)$ resonances.
Categories: nucl-th