Study $\omega$ and $\phi$ photoproduction in the nucleon isotopic   channels
  We present results for the photoproduction of $\omega$ and $\phi$ meson in the nucleon isotopic channles. A recently developed quark model with an effective Lagrangian is employed to account for the non-diffractive {\it s}- and {\it u}-channel processes; the diffractive feature arising from the {\it natural} parity exchange is accounted for by the {\it t}-channel pomeron exchange, while the {\it unnatural} parity exchange is accounted for by the {\it t}-channel pion exchange. In the $\omega$ production, the isotopic effects could provide more information concerning the search of "missing resonances", while in the $\phi$ production, the isotopic effects could highlight non-diffractive resonance excitation mechanisms at large angles. 
Q. Zhao