Color confinement and the quantum-chromodynamic vacuum. II. Gluon propagation and the Coulomb interaction

In an earlier paper the color-confining interaction was identified as the vacuum expectation value of the modified Coulomb operator. This vacuum expectation value is related first to the QCD running coupling constant and then to the gluon propagator in the physical vacuum. If the propagator is less singular at p=0 than predicted from perturbation theory, the required infrared singularity in the interaction arises naturally. Nonperturbative solutions for both the running coupling constant and the modified Coulomb interaction are presented.