Upper limits on<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>φ</mml:mi><mml:mi>φ</mml:mi></mml:math>production in 350-GeV/<i>c</i>proton-beryllium collisions

We have established a sensitive upper limit on $\ensuremath{\varphi}\ensuremath{\varphi}$ resonance production by 350-GeV/c protons incident on a beryllium target. The 90%-confidence-level upper limit varies from 1.5\ifmmode\times\else\texttimes\fi{}${10}^{\ensuremath{-}30}$ ${\mathrm{cm}}^{2}$/nucleon at ${M}_{\ensuremath{\varphi}\ensuremath{\varphi}}=2.8$ ${\mathrm{G}\mathrm{e}\mathrm{V}/\mathit{c}}^{2}$ to 6.0\ifmmode\times\else\texttimes\fi{}${10}^{\ensuremath{-}32}$ ${\mathrm{cm}}^{2}$/nucleon at ${M}_{\ensuremath{\varphi}\ensuremath{\varphi}}=3.4$ ${\mathrm{G}\mathrm{e}\mathrm{V}/\mathit{c}}^{2}$. We observe no evidence of the ${\ensuremath{\eta}}_{c}$.