Dynamical symmetry breaking and tight bound states in quantum field theory

Dynamic symmetry breaking in quantum field theory is considered. It is shown that there is an essential difference between the dynamics with small (γm<1) anomalous dimension of the composite operator anti ψψ and that with γm≥1. The latter leads to spinless tight bound states which play an important role in critical scaling laws at short distances. The application of this analysis to computer simulations of lattice quenched QED is considered. Consequences of such dynamics for walking technicolor are discussed. (orig.)