Massless Limit of the Massive Yang-Mills Field

Abstract

The Feynman rules for the massive Yang-Mills field for tree and one-loop diagrams are recast into forms for which the limit as the mass goes to zero can be immediately obtained when the external particles are transversely polarized. Explicit calculations show, however, that the resulting rules cannot be taken to be the correct rules for the massless theory, lest unitarity and Lorentz invariance be violated.