The Chiral Anomaly and High-energy Scattering in Qcd

Infra-red properties of the triangle anomaly and the “anomaly pole” are elaborated and applied to the study of high-energy scattering in QCD, when the gauge symmetry is partially broken to SU(2). It is shown that the chiral flavor anomaly provides a wee-gluon component for Goldstone bosons that combines with interactions due the U(1) anomaly to produce an infra-red transverse momentum scaling divergence in scattering amplitudes. After the divergence is factorized out, as a condensate, the remaining physical amplitudes have confinement and chiral symmetry breaking. A lowest-order contribution to the pion scattering amplitude is calculated in detail. Although originating from very complicated diagrams, the amplitude has a remarkable (semi-)perturbative simplicity. The momentum structure is that of single gluon exchange but zero momentum quarks inject additional spin and color structure via anomaly interactions. Work supported by the U.S. Department of Energy, Division of High Energy Physics, Contracts W-31-109-ENG-38 and DEFG05-86-ER-40272 [email protected]