Production of<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>φ</mml:mi></mml:math>and<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>ω</mml:mi></mml:math>Mesons in Near-Threshold<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi mathvariant="italic">pp</mml:mi></mml:math>Reactions

The ratio of the exclusive production cross sections for $\ensuremath{\varphi}$ and $\ensuremath{\omega}$ mesons has been measured in $\mathrm{pp}$ reactions at ${T}_{\mathrm{beam}}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}2.85\phantom{\rule{0ex}{0ex}}\mathrm{GeV}$. The observed $\ensuremath{\varphi}/\ensuremath{\omega}$ ratio is $(3.7\ifmmode\pm\else\textpm\fi{}{0.7}_{\ensuremath{-}0.9}^{+1.2})\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}3}$. 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 $\ensuremath{\sim}3$ previously observed at higher energies. The modest increase of this enhancement near the production threshold is compared to the much larger increase of the $\ensuremath{\varphi}/\ensuremath{\omega}$ ratio observed in specific channels of $\overline{p}p$ annihilation experiments.