Recent progress in the solution of Schwinger-Dyson equations (SDE), as well
as lattice simulation of pure glue QCD, indicate that the gluon propagator and
coupling constant are infrared (IR) finite. We discuss how this
non-perturbative information can be introduced into the QCD perturbative
expansion in a consistent scheme, showing some examples of tree level hadronic
reactions that successfully fit the experimental data with the gluon propagator
and coupling constant depending on a dynamically generated gluon mass. This
infrared mass scale acts as a natural cutoff and eliminates some of the ad hoc
parameters usually found in perturbative QCD calculations. The application of
these IR finite Green's functions in the case of higher order terms of the
perturbative expansion is commented.Comment: Talk at International Workshop on QCD Green's Functions, Confinement
and Phenomenology, September 7-11, 2009, ECT, Trento, Italy, 12 pages, 7
figure