  We study the double-diffractive production of various heavy systems (e.g.
Higgs, dijet, t tbar and SUSY particles) at LHC and Tevatron collider energies.
In each case we compute the probability that the rapidity gaps, which occur on
either side of the produced system, survive the effects of soft rescattering
and QCD bremsstrahlung effects. We calculate both the luminosity for different
production mechanisms, and a wide variety of subprocess cross sections. The
results allow numerical predictions to be readily made for the cross sections
of all these processes at the LHC and the Tevatron collider. For example, we
predict that the cross section for the exclusive double-diffractive production
of a 120 GeV Higgs boson at the LHC is about 3 fb, and that the QCD background
in the b bbar decay mode is about 4 times smaller than the Higgs signal if the
experimental missing-mass resolution is 1 GeV. For completeness we also discuss
production via gamma gamma or WW fusion.
