Infrared subtleties and chiral vertices at NLO: an implicit regularization analysis

Abstract

We employ implicit regularization (IReg) in quark-antiquark decays of the Z, or of a scalar (CP-even or odd) boson at NLO, and compare with dimensional schemes to reveal subtleties involving infrared divergence cancellation and γ5-matrix issues. Besides the absence of evanescent fields in IReg, such as -scalars required in certain schemes that operate partially in the physical dimension, we verify that our procedure preserves gauge invariance in the presence of the γ5 matrix without requiring symmetry preserving counterterms while the amplitude is infrared finite as stated by the KLN theorem.