ABSTRACT
This chapter discusses the production of vector mesons by photons, and the simpler problem of photon-vector meson coupling. Values for the various constants for the vector meson may be found in the Particle Properties Table. Interaction of photons of small q2 is very strongly influenced by the nearby poles at the mass of the vector mesons. Substantial parts of the interaction can be understood as being due to intermediate virtual vector meson coupling – but, of course, not all the coupling can be so described. The VDM theory predicts rapid variations in with energy, whereas experiments indicate only a small variation, if any. There is at present no explanation known for this discrepancy – its study would make a nice problem.
