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 analysis of the $\gamma p\to \eta {\pi }^{0}p$ reaction has been performed using data from the GRAAL experiment. The total and differential cross sections and the beam asymmetry have been obtained from threshold up to 1.5 GeV of beam energy. The two resonances $S_{11}(1535)$ and $\Delta (1700)$ are expected to be excited in the intermediate states of this reaction. The results are used to test predictions based on the assumption that both resonances are dynamically generated from the meson-baryon interaction provided by chiral Lagrangians. The term involving the $\Delta (1700)$ excitation, followed by the decay into $\eta \Delta (1232)$, is found to be dominant.

We present new break-up and coherent data for $\eta$ meson photoproduction on the deuteron, using a deuterium target and tagged bremsstrahlung photons up to 1 GeV. The differential cross sections for the coherent process were measured from threshold to 800 MeV. They are much smaller than those previously reported. The break-up channel provides a direct measurement of the neutron to proton differential cross section ratios. At the $S_{11}\left(1535\right)$ resonance peak, ${\sigma }_n/{\sigma }_p=0.68\mathrm{}\pm 0.06$ leading to an isoscalar to isovector amplitude ratio of $A_s{/A}_{\upsilon }=0.096\mathrm{}\pm 0.02$.

The photoproduction of the $\omega$ meson has been studied at GRAAL from threshold up to a photon energy of 1.5 GeV. The differential cross sections and beam asymmetries have been measured precisely at all angles. The total cross section is also obtained. Systematic enhancements of the differential cross section at large angles and nonzero beam asymmetries at intermediate angles provide clear evidence for $s$- and $u$-channel resonant processes. The data are compared to the results of hadron and quark models.