The aim of these studies is to use hard (large Q[sup 2]) processes to investigate the partonic nature of the pomeron. We have measured events with large rapidity gaps between balancing high E[sub T] jets, events with two forward (same-side) jets and a large gap (diffractive di-jet production), diffractive W[sup[+-]] production and diffractive heavy flavor (J/[psi] and b-quark) production. Candidate events of the type double-pomeron[yields] di-jet are observed. I close with a look at the future (Run II).

The aim of these studies is to use hard (large Q2) processes to investigate the partonic nature of the pomeron. We have measured events with large rapidity gaps between balancing high E{sub T} jets, events with two forward (same-side) jets and a large gap (diffractive di-jet production), diffractive W{sup {+-}} production and diffractive heavy flavor (J/[psi] and b-quark) production. Candidate events of the type double-pomeron → di-jet are observed. I close with a look at the future (Run II).

Results on diffractive W-boson and dijet production, selected with a rapidity gap in the forward detector region, are briefly summarized. The new sample of Run 1C data with a Roman Pot trigger has been analyzed for dijet production in single diffraction and double pomeron exchange. Comparisons of diffractive to non-diffractive dijet events are presented.

We review published rapidity gap results on diffractive W and dijet production and discuss new results on diffractive b and J/[psi] production. The diffractive structure function of the proton obtained from Roman pot dijet data is presented and com- pared with expectations based on the diffractive parton densities extracted from DIS at HERA. Also presented are results on dijet production in double Pomeron exchange. Finally, we review hard double-diffractive results (rapidity gaps between jets) and present new results on soft double diffraction.

Results on soft and hard diffraction obtained by the CDF Collaboration in Run I of the Fermilab Tevatron {bar p}p collider are reviewed and compared with results from the DESY ep collider HERA and with theoretical expectations. In addition, the CDF program for diffractive studies in Run II is briefly reviewed with emphasis on the relevant detector upgrades and physics goals.

Results on soft and hard diffraction obtained by the CDF Collaboration in Run 1 of the Fermilab Tevatron {bar p}p collider are presented. Comparisons are made with theoretical predictions and with results from the DESY ep collider HERA.

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.