  In the prospect of diffractive Higgs production at the LHC collider, we give
an extensive study of Higgs boson, dijet, diphoton and dilepton production at
hadronic colliders via diffraction at both hadron vertices. Our model, based on
non factorizable Pomeron exchange, describes well the observed dijet rate
observed at Tevatron Run I. Taking the absolute normalization from data, our
predictions are given for diffractive processes at Tevatron and LHC. Stringent
tests of our model and of its parameters using data being taken now at Tevatron
Run II are suggested. These measurements will also allow to discriminate
between various models and finally to give precise predictions on diffractive
Higgs boson production cross-section at the LHC.
