Production of ω and φMesons in Near-Threshold πN Reactions: Baryon Resonances and the Okuba-Zweig-Iizuka Rule

Results of a combined analysis are presented for the production of ω and φ mesons in π reactions in the near-threshold region using a conventional "nonstrange" dynamics based on processes that are allowed by the nonideal ω-φ mixing. We show that the interferences of the t channel (meson exchange) and s, u channels (nucleon and nucleon-resonances) differ significantly for the ω and φ production amplitudes. This leads to a decrease of the relative yields, in comparison with the expectations based on a one-component amplitude with standard ω-φ mixing.
We find a strong and nontrivial difference between observables in ω and φ production reactions caused by the different roles of the nucleon and nucleon-resonance amplitudes. A series of predictions for the experimental study of this effect is presented.