ω and ρ photoproduction with an effective quark model Lagrangian

A unified approach to vector meson photoproductions is presented in the constituent quark model. The s- and u-channel resonance contributions are generated using an effective quark vector-meson Lagrangian. Taking into account π0 and σ t-channel exchanges for diffractive production in ω and ρ0 productions respectively, the available total and differential cross section data for ω, ρ0, ρ+, and ρ− photoproduction can be well described with the same set of parameters in the quark model. Our results clearly indicate that polarization observables are essential to identify so-called “missing” resonances.