**Titre**

Aspects of Diffractive Physics

Introduction of non-perturbative effects

**Résumé
**

We think of this
work as a basis, a kind of manual or short report on topics, tools and
methods for diffractive high-energy calculations and as an example of
what is possible to do, but also as a bridge to new approaches to the
introduction of non-perturbative effects and to more complex
calculation.

We introduce the
necessary ingredient to understand diffractive production. The first
chapter is an introduction to cutting rules, Feynman diagrams and we
shall see that the main part of the cross-section information is given
by the imaginary part of these diagrams. After the introduction of our
technique of calculation we come to the pomeron physics and introduce
the approach of our futur calculation. The last subsection is devoted
to the first step in the direction of the Higgs diffractive production,
a two-loop diagram as a basis of our future works. The last chapter
will contain an original result. We know that QCD has some
problems especially with non-perturbative phenomena i.e. long-distance
events. A long-time ago, Gribov introduced the idea of a modified gluon
propagator that includes non-perturbative effects in the usual
calculation of the amplitude. Then, we shall take this Gribov propagator and perform the
calculation of the two-gluon exchange with it. We conclude by a review
of the improvement needed in the calculation and the new aspects of the
amplitude.