Aspects of confinement from QCD correlation functions

Understand

We discuss the properties of ghost and gluon propagators in Landau gauge Yang-Mills theory and their relation to the confinement problem.

• In general two types of infrared behavior of these functions are allowed from their functional equations: scaling and decoupling.
• Both solutions show positivity violations in the gluon propagator and lead to a confining Polyakov loop potential.
• However, only the scaling solution agrees with the Kugo-Ojima confinement scenario and the related formulation of a physical Hilbert space of Yang-Mills theory.