Production of phi and omega mesons in near-threshold pp reactions

The ratio of the exclusive production cross sections for phi and omega mesons has been measured in pp reactions at T-beam = 2.85 GeV. The observed phi/omega ratio is (3.7 +/- 0.7(-0.9)(+1.2)) X 10(-3). After phase space corrections, this ratio is about a factor of 10 enhanced relative to naive predictions based upon the Okubo-Zweig-Iizuka rule, in comparison to an enhancement by a factor of similar to 3 previously observed at higher energies. The modest increase of this enhancement near the production threshold is compared to the much larger increase of the phi/omega ratio observed in specific channels of <(p)over bar p> annihilation experiments.