Production of $ω$ and $ϕ$ Mesons in Near-Threshold $πN$ Reactions: Baryon Resonances and Validity of the OZI Rule

Abstract

Results of a combined analysis are presented for the production of $ω$ and $ϕ$ mesons in $πN$ reactions in the near-threshold region using throughoutly a conventional ''non-strange'' dynamics based on such processes which are allowed by the non-ideal $ω-ϕ$ mixing. We show that strong interferences of the $t$ (meson exchange) and $s$ and $u$ (nucleon and nucleon resonance) channels differ significantly in $ω$ and $ϕ$ production amplitudes. This leads to a decrease of the relative yields in comparison with expectations based on one-channel models with standard $ω- ϕ$ mixing. We find a strong and non-trivial difference between observables in $ω$ and $ϕ$ production reactions caused by the different role of the nucleon and nucleon resonance amplitudes. A series of predictions for the experimental study of this effect is presented.