Dijet Production by Color-Singlet Exchange at the Fermilab Tevatron

We report a new measurement of dijet production by color-singlet exchange in p{ovr p} collisions at {radical}(s)=1.8 TeV at the Fermilab Tevatron. In a sample of events with two jets of transverse energy E{sup jet}{sub T}{gt}20 GeV , pseudorapidity in the range 1.8{lt}{vert_bar}{eta}{sup jet}{vert_bar}{lt}3.5 , and {eta}{sub 1}{eta}{sub 2}{lt}0 , we find that a fraction R=[1.13{plus_minus}0.12(stat){plus_minus} 0.11(syst)]{percent} has a pseudorapidity gap within {vert_bar}{eta}{vert_bar}{lt}1 between the jets that can be attributed to color-singlet exchnage. The fraction R shows no significant dependence on E{sup jet}{sub T} or on the pseudorapidity separation between the jets. {copyright} {ital 1998} {ital The American Physical Society}