  We present the first NLO QCD analysis of single-diffractive dijet production
in proton-antiproton collisions. By comparing the ratio of single- and
non-diffractive cross sections to data from the Tevatron, the rapidity-gap
survival probability is determined as a function of the momentum fraction of
the parton in the antiproton. Assuming Regge factorization, this probability
can be interpreted as a suppression factor for the diffractive structure
function measured in deep-inelastic scattering at HERA. In contrast to the
observations for photoproduction, the suppression factor in proton-antiproton
collisions depends on the momentum fraction of the parton in the Pomeron even
at NLO.
