Analysis of Photoproduction of Vector Mesons

The photoproduction of neutral vector mesons, in the reactions $\gamma +p\to V+p$ and $\gamma +p\to V+N^{*+}\mathrm{}\left(1238\right)\mathrm{}$ at photon momenta of a few BeV/c, is discussed in terms of the one-particle-exchange and absorption models. Initial- and final-state interaction effects are included. The absorptive amplitudes are calculated by recourse to the unitarity equation. Difficulties arising in this calculation associated with Born amplitudes involving particles of high spin are discussed in detail. The analysis indicates that both the one-particle-exchange and absorptive mechanisms fail to account for the observed $\rho$ photoproduction data. On the other hand, the presently available $\omega$ photoproduction data are found to be consistent with the one-pion-exchange model, corrected for absorption in the final state.