Asymmetry in omega meson photoproduction and the phase of omega-pi-gamma coupling

We analyze the double polarization asymmetry of the omega-meson photoproduction in the vector-meson-dominance model of diffractive production and the one-pion exchange model. We find that the longitudinal beam-target asymmetry is very sensitive to the real part of the diffractive photoproduction amplitude and to the sign of the omega-pi-gamma coupling because of the different spin structures of the amplitudes associated with the different mechanisms.