Dijet Production by Color-Singlet Exchange at the Fermilab Tevatron

We report a new measurement of dijet production by color-singlet exchange in $p\overline{p}$ collisions at $\sqrt{s}=1.8\mathrm{}\mathrm{TeV}$ at the Fermilab Tevatron. In a sample of events with two jets of transverse energy $E_T^{\mathrm{jet}}>20\mathrm{}\mathrm{GeV}$, pseudorapidity in the range $1.8<\mathrm{}|{\eta }^{\mathrm{jet}}|<3.5\mathrm{}$, and ${\eta }_1{\eta }_2<0\mathrm{}$, we find that a fraction $R=[1.13\pm 0.12(\mathrm{stat})\pm 0.11(\mathrm{syst}\left)\right]\%$ has a pseudorapidity gap within $|\eta |<1\mathrm{}$ between the jets that can be attributed to color-singlet exchnage. The fraction $R$ shows no significant dependence on $E_T^{\mathrm{jet}}$ or on the pseudorapidity separation between the jets.