Hadron-hadron collisions at extreme energies: Light-cone QCD with an axial-vector anomaly current and an infrared fixed point

Abstract

We argue that QCD with the maximum number of fermions allowed by asymptotic freedom provides a ''parton-model'' description of soft high-energy collisions. That is, infinite-momentum quantization can be based on the perturbative vacuum and yet produce confinement and chiral-symmetry breaking. A first-stage infrared construction gives SU(2) gauge invariance and confinement. An infrared fixed point produces transverse momentum scaling and associated infrared divergences which couple to an anomaly-current component of a Fock-space wave function. The divergences factor on to color-zero states allowing the wave function zeros needed by transverse gauge invariance. Parton interactions are dominated by fermion-loop anomalies coupled to the divergences. As a result a pion has a vector valence-quark component. The infrared limit giving SU(3) gauge invariance is argued to be accompanied by critical-Pomeron high-energy behavior and spontaneous chiral-symmetry breaking, but is only briefly discussed in this paper.