We present new results from studies on diffractive dijet production and exclusive production of dijet and diphoton obtained by the CDF Collaboration in proton-antiproton collisions at the Fermilab Tevatron.

Proceedings of the NATO Advanced Research Workshop, Alushta, Crimea, Ukraine, from 31 August to 6 September 2002

Results on soft and hard diffraction obtained by the CDF Collaboration at the Fermilab Tevatron {bar p}p Collider are reviewed with emphasis on aspects of the data that point to the underlying QCD mechanism for diffraction. The results are interpreted in terms of a phenomenological approach in which diffraction is due to an exchange of low-x partons subject to color constraints.

Experimental results on hard diffraction from CDF and D0 at the Tevatron are reviewed and compared with results from H1 and ZEUS at HERA and with theoretical expectations.

The diffractive program of the CDF Collaboration at the Fermilab Tevatron p{bar p} Collider is reviewed with emphasis on recent results from Run II at {radical}s = 1.96 TeV. Updated results on the x{sub B{sub j}} and Q{sup 2} dependence of the diffractive structure function obtained from dijet production, and on the slope parameter of the t-distribution of diffractive events as a function of Q{sup 2} in the range 1 GeV{sup 2}

Hard diffraction in events with dijets and rapidity gaps has been studied by D0 and CDF for three processes: hard color singlet exchange, hard single diffraction, and hard double pomeron exchange, using Tevatron [anti p]p data at [radical]s = 630 GeV and 1.8 TeV. Measurements of rates, [eta], E[sub T] and [radical]s dependencies are presented and comparisons made with predictions of several models.