Massive gluons in Curci-Ferrari model for describing infrared QCD

At large energy quarks and gluons behave as free particles and therefore the standard perturbative analysis of QCD gives very good results. However, this is not the situation in the low energy regime of QCD which is generally treated with nonperturbative methods. In spite of this, lattice simulations observe that the expansion parameter is not large in the gluonic sector. In particular, the coupling constant do not reach a Landau pole in the infrared as it is expected by standard perturbation theory. On top of this, lattice simulations find that the gluon propagator behaves as a massive propagator in the infrared. Motivated by these observations we use a model that includes a mass for the gluon (Curci-Ferrari) that can reproduce the same kind of behaviour for the gluon propagator and also a similar expansion parameter as the one found by the lattice. In this proceeding we show some of the results of quenched correlation functions obtained by using that small parameter for computing one and two loops corrections. At the end, we compare them with lattice data obtaining very good results