Study of baryon resonances through γp→ηpdifferential cross sections

We present new data for the γp→ηp reaction at average photon energies of 729 and 753 MeV. The reaction is believed to be dominated by intermediate states of ${\mathit{N}}^{\mathrm{*}}$ resonances and should be an excellent way to study the internal structure of the baryon states. Previously published data were consistent with a dominance of the ${\mathit{S}}_{11}$(1535)${\mathit{N}}^{\mathrm{*}}$ resonance intermediate states in the reaction mechanism. The new data show deviations from this picture for the first time.