Coherentπ0andηphotoproduction on the deuteron

Coherent pion photoproduction, $d(\gamma ,{\pi }^0)d$, is calculated in a coupled channels approach in momentum space using an elementary production operator that includes Born terms, vector meson exchange, and $M1/E2\mathrm{}$ $\Delta$-resonance excitation. The final state interaction is treated in the Kerman-McManus-Thaler multiple scattering approach that describes $\pi d$ elastic scattering well. Differential cross sections are found to agree well with existing $(\gamma ,{\pi }^0)$ data. The polarization observables $\Sigma {,iT}_{11}$ and the tensor analyzing powers are predicted for forthcoming experiments. A number of transparent relationships between polarization observables and the elementary production operator is derived. Finally, calculations are performed for coherent $\eta$ photoproduction, $d(\gamma ,\eta )d$, in the threshold region which agree well with a very recent Mainz experiment.