We extract diffractive parton densities from data on diffractive deep inelastic scattering (DIS) and on diffractive photoproduction of jets. We explore the results of several Ansätze for the functional form of the parton densities. Then we use the fitted parton densities to predict the diffractive production of jets and of $W$’s and $Z$’s in $p\overline{p}$ collisions at the Fermilab Tevatron. To fit the photoproduction data requires a large gluon density in the Pomeron. The predictions for the Tevatron cross sections are substantially higher than data; this signals a breakdown of hard-scattering factorization in diffractive hadron-hadron collisions.

• Received 24 January 1997

DOI:https://doi.org/10.1103/PhysRevD.59.074022