Chiral symmetry breaking from glue in light-front QCD.

Abstract : A constituent picture of hadrons may emerge from light-front QCD without zero modes, but a perturbatively renormalized hamiltonian will not reproduce light mesons. Chiral symmetry breaking looks quite different in light-front coordinates than its familiar equal time or euclidean form, and simple arguments lead to the conclusion that gluons in the pion are essential. It is possible to estimate the minimal amount of glue required to produce massless pions using quark-antiquark calculations and the assumption that only local interactions are required to produce light-front chiral symmetry breaking effects.