An effective low energy action for Yang-Mills theories is proposed, wh
ich invokes an additional auxiliary field H-mu nu for the field streng
th F-mu nu. For a particular relation between the parameters of this a
ction a gluon propagator with a 1/p(4) behaviour for p(2) --> 0 in the
Landau gauge is obtained. The abelian subsector of this action admits
a duality transformation, where the dual action contains a Goldstone
boson phi as the dual of H-mu nu, and corresponds to an abelian Higgs
model in the broken phase describing the condensation of magnetic char
ges. The Wilsonian renormalization group equations for the parameters
of the original action are integrated in some approximation, and we fi
nd that the relation among the parameters associated with confinement
appears as an infrared attractive fixed point. (C) 1998 Elsevier Scien
ce B.V.