Dynamical symmetry breakdown in two-dimensional quantum chromodynamics. III. The physical space

Abstract

Some physical features of the solutions to (1+1)-dimensional SU(N) quantum chromodynamics presented by us in two earlier papers are studied in this final part of our trilogy. Those solutions were defined in indefinite-metric spaces, out of which positive-metric ones were constructed in the usual way. We study operators in these physical spaces. The S[U(1)]^N part of the SU(N) symmetry group that was left unbroken in the indefinite-metric solution is found to be fully broken down here. The vacuum structure is elucidated and different sectors are identified. Massless quarks are shown to be color screened but not confined (i.e., there is a free, colorless fermion having the same fermion number as the quark). Massive quarks are confined.