Ghost dissection

Abstract

We show that a necessary condition to have a positive Landau-gauge ghost propagator in d=2 Yang-Mills theories is a vanishing zero-momentum gluon propagator. Our proof is based on a careful scrutinizing of the ghost Dyson-Schwinger equation. Said otherwise, the Gribov no-pole condition forbids the occurrence of the "decoupling/massive" gluon propagator solution in d=2, in sharp contrast with d=3 and 4, but consistent with state-of-the-art lattice data.

12 pages. Talk given by D.Dudal at International Workshop on QCD Green's Functions, Confinement and Phenomenology, September 05-09, 2011 (Trento, Italy)