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.

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.

A comprehensive and up-to-date overview of soft and hard diffraction processes in strong interaction physics. The first part covers soft hadron—hadron scattering in a complete and mature presentation. It can be used as a textbook in particle physics classes. Chapters 8-11 address graduate students as well as researchers, covering the "new diffraction": the pomeron in QCD, low-x physics, diffractive deep inelastic scattering and related processes.

Experimental results of hard single diffraction and double pomeron exchange studies at the Fermilab Tevatron p{bar p} collider are presented. Single diffraction results are compared with predictions from phenomenological models and expectations from results obtained in diffractive deep inelastic scattering experiments at the DESY ep collider HERA. Double pomeron exchange results are compared with corresponding single diffraction results to test factorization.

Preliminary results on jet production with rapidity gaps in p{anti p} collisions are presented for both D0 and CDF. An excess of events with a forward rapidity gap is observed at both (square root)s=1800 GeV and 630 GeV, consistent with a hard single diffractive process. The first evidence for diffractive W production is presented. A class of events with two forward gaps and central dijets is observed at (square root)s=1800 GeV, a topology that is consistent with hard double pomeron exchange. Kinematic properties of events containing rapidity gaps are measured.

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.

Results on diffractive particle interactions from the Fermilab Tevatron {bar p}p collider are placed in perspective through a QCD inspired phenomenological approach, which exploits scaling and factorization properties observed in data. The results discussed are those obtained by the CDF Collaboration from a comprehensive set of single, double, and multigap soft and hard diffraction processes studied during the twenty year period since 1985, when the CDF diffractive program was proposed and the first Blois Workshop was held.