
We study chiral symmetry breaking using the standard gap equation, supplemented with the infraredfinite gluon propagator and ghost dressing function obtained from largevolume lattice simulations. One of the most important ingredients of this analysis is the nonabelian quarkgluon vertex, which controls the way the ghost sector enters into the gap equation. Specifically, this vertex introduces a numerically crucial dependence on the ghost dressing function and the quarkghost scattering amplitude. This latter quantity satisfies its own, previously unexplored, dynamical equation, which may be decomposed into individual integral equations for its various form factors. In particular, the scalar form factor is obtained from an approximate version of the 'oneloop dressed' integral equation, and its numerical impact turns out to be rather considerable. The detailed numerical analysis of the resulting gap equation reveals that the constituent quark mass obtained is about 300 MeV, while fermions in the adjoint representation acquire a mass in the range of (750962) MeV.
