Color confinement and long-distance color fields in QCD

We use an effective lagrangian previously derived from a long-distance self-consistent solution of the Schwinger-Dyson equations of Yang-Mills theory to study some long-distance problems in QCD. In particular we show: (I) the long-distance contribution to the energy of a system containing a net color electric charge is infinite and hence there are no such states in the physical spectrum; (II) the long-distance contribution to the energy of a system containing a net color magnetic charge is completely screened at distances r > 1/Λsub(QCD). (orig.)