Observation of Rapidity Gaps inp¯pCollisions at 1.8 TeV

In $p\overline{p}$ collisions at $\sqrt{s}=1.8$ TeV we find jet events with a rapidity gap topology. The number of hadrons in the rapidity interval $\ensuremath{\Delta}{\ensuremath{\eta}}_{D}$ between leading-jet cones was sampled by charged tracks with ${P}_{T}g400$ MeV/c. We find excess trackless events beyond that expected in a smooth multiplicity distribution. In a control region outside $\ensuremath{\Delta}{\ensuremath{\eta}}_{D}$ we see no excess. For $\ensuremath{\Delta}{\ensuremath{\eta}}_{D}g0.8$, the fraction of excess trackless events, consistent with estimates based on exchange of color-singlet digluons, is $R(\mathrm{gap})=\frac{{\ensuremath{\sigma}}_{\mathrm{jet}}(\mathrm{gap})}{{\ensuremath{\sigma}}_{\mathrm{jet}}}=0.0085\ifmmode\pm\else\textpm\fi{}{0.0012(\mathrm{stat})}_{\ensuremath{-}0.0012}^{+0.0024}(\mathrm{syst})$.