Chirality violation in QCD Reggeon interactions

The appearance of the triangle graph infrared axial anomaly in reduced quark loops contributing to QCD triple-Regge interactions is studied. In a dispersion relation formalism, the anomaly can only be present in the contributions of unphysical triple discontinuities. In this paper an asymptotic discontinuity analysis is applied to high-order Feynman diagrams to show that the anomaly does indeed occur in sufficiently high-order Reggeized gluon interactions. The Reggeon states involved must contain Reggeized gluon combinations with the quantum numbers of the anomaly (winding-number) current. A direct connection with the well-known U(1) problem is thus established. Closely related diagrams that contribute to the pion or Pomeron and triple Pomeron couplings in color superconducting QCD are also discussed.