We present new $\Sigma$ beam asymmetry data for $\eta$ meson photoproduction on the proton, using a novel tagged, laser backscattered, linearly polarized photon beam up to 1.1 GeV. The data show large, positive asymmetries, at all incident photon energies. In addition to the $S_{11}\left(1535\right)$ and $D_{13}\left(1520\right)$ resonances necessary to reproduce the cross sections, $P_{13}\left(1720\right)$ and $D_{15}\left(1675\right)$ “four stars” resonances contribute to the $\Sigma$ observable, but cannot reproduce the strong forward asymmetries measured at energies higher than 900 MeV.

The differential cross section for the reaction p(gamma, etap) has been measured from threshold to 1100 MeV photon laboratory energy. For the first time, the region of the S-11(1535) resonance is fully covered in a photoproduction experiment and will allow a precise extraction of its parameters at the photon point. These high precision data together with the already measured beam asymmetry data will provide stringent constraints on the extraction of new couplings of baryon resonances to the eta meson. (C) 2002 Elsevier Science B.V. All rights reserved