Confinement, chiral symmetry breaking and Faddeev–Niemi decomposition in QCD

We identify two distinct, complementary classes of gauge field configurations for QCD with SU(2) gauge group, one (instanton-like configurations) having to do with chiral symmetry breaking but not with confinement, the other (regularized Wu–Yang monopoles) very likely responsible for confinement but unrelated to chiral symmetry breaking. Our argument is based on a semiclassical analysis of fermion zero modes in these backgrounds, made by use of a gauge field decomposition recently introduced by Faddeev and Niemi. Our result suggests that the two principal dynamical phenomena in QCD, confinement and chiral symmetry breaking, are distinct effects, caused by two competing classes of gauge field configurations.