Production of $\phi$ and $\omega$ Mesons in Near-Threshold $\mathit{pp}$ Reactions

The ratio of the exclusive production cross sections for $\phi$ and $\omega$ mesons has been measured in $\mathrm{pp}$ reactions at $T_{\mathrm{beam}}=2.85\mathrm{GeV}$. The observed $\phi /\omega$ ratio is $(3.7\pm {0.7}_{-0.9\mathrm{}}^{+1.2\mathrm{}})\times {10}^{-3\mathrm{}}$. 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 $\sim 3$ 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 $\overline{p}p$ annihilation experiments.