Multivacuum states in a fermionic gap equation with massive gluons and confinement

Abstract

We study the nontrivial solutions of the Quantum Chromodynamics (QCD) fermionic gap equation (FGE) including the contribution of dynamically massive gluons and the confining propagator proposed by Cornwall. Without the confining propagator, in the case of nonrunning gluon mass (m(g)), we found the multivacuum solutions (replicas) reported in the literature and we were able to define limits on m(g) for dynamical chiral symmetry breaking (CSB). On the other side, when considering the running in the gluon mass the vacuum replicas are absent in the limits on m(g) where the chiral symmetry is broken. In the pure confining sector, the multivacuum states are always absent so it is said that only one stable solution for the gap equation is found as claimed in previous analysis using different approaches. Finally, in the case of the complete gap equation i.e. with both contributions, the vacuum replicas are also absent in both cases; with constant and with running gluon mass.