Infrared finite quark propagator and chiral symmetry breaking in QCD

The Schwinger-Dyson equation for the quark propagator with the help of the corresponding Slavnov-Taylor identity is investigated in the infrared region. Confinement is implemented by assuming that the gluon propagator in the Landau gauge becomes an infrared singular like (q2)-2 at small momenta. Making a special assumption on the ghost-gluon vertex function, we obtain an infrared finite quark propagator, which has no pole and satisfies the chiral symmetry breaking condition. This model is free of ghost complications. (orig.)