From unphysical gluon and ghost propagators to physical glueball propagators (in the Gribov-Zwanziger picture): a not so trivial task?

Understand

During recent years, a good agreement was found between the analytical derivation and the numerical simulation of the Landau gauge gluon and ghost propagators.

• We mention the Schwinger-Dyson and Gribov-Zwanziger formalism for the analytical work.
• Although the agreement between several approaches is nice, these propagators do not correspond to the relevant physical degrees of freedom.
• In the case of pure gauge theories, one should start to study the glueball correlators.