Infrared Behaviour of Propagators and Vertices

الأصل · EN

We elucidate constraints imposed by confinement and dynamical chiral symmetry breaking on the infrared behaviour of the dressed-quark and -gluon propagators, and dressed-quark-gluon vertex. In covariant gauges the dressing of the gluon propagator is completely specified by P(k²):= 1/[1+Pi(k²)], where Pi(k²) is the vacuum polarisation. In the absence of particle-like singularities in the dressed-quark-gluon vertex, extant proposals for the dressed-gluon propagator that manifest P(k²=0)=0 and Max[P(k²)] 10 neither confine quarks nor break chiral symmetry dynamically. This class includes all existing estimates of P(k²) via numerical simulations.