A low-energy effective Yang-Mills theory for quark and gluon confinement

Understand

We derive a gauge-invariant low-energy effective model of the Yang-Mills theory.

• We find that the effective gluon propagator belongs to the Gribov-Stingl type and agrees with it when a mass term which breaks nilpotency of the BRST symmetry is included.
• We show that the effective model with gluon propagator of the Gribov-Stingl type exhibits both quark and gluon confinement: the Wilson loop average has the area law and the Schwinger function violates reflection positivity.
• However, we argue that both quark and gluon confinement can be obtained even in the absence of such a mass term.