Photoproduction ofωMesons from Complex Nuclei

Photoproduction of $\omega$ mesons from Be, C, Al, Cu, and Pb has been studied at a mean energy of 6.8 GeV. The $t$ distributions show a forward peak characteristic of a coherent diffraction mechanism, but also a considerable cross section at large $t$ characteristic of an incoherent production mechanism. The ratio of cross sections for coherently photoproduced ${\rho }^0$ mesons to $\omega$ mesons is 11.8 ± 1.3 compared with the simple SU(3) prediction of 9.