Percolation and critical behaviour in SU(2) gauge theory

The paramagnetic-ferromagnetic transition in the Ising model can be describ ed as percolation of suitably defined clusters. We have tried to extend suc h picture to the confinement-deconfinement transition of SU(2) pure gauge t heory, which is in the same universality class of the Ising model. The clus ter definition is derived by approximating SU(2) by means of Ising-like eff ective theories. The geometrical transition of such clusters turns out to d escribe successfully the thermal counterpart for two different lattice regu larizations of (3 + 1)-d SU(2).