1997/08/31 by Gordon Chalmers, G. Chalmers, Warren Siegel +1 · 2 citations
Physics and Astronomy · #Black Holes and Theoretical Physics #Noncommutative and Quantum Gravity Theories #Particle physics theoretical and experimental studies #hep-ph #hep-th
paper · pdf · doi:10.1103/physrevd.59.045012
published as Phys.Rev. D59 (1999) 045012 · 14 pg., plain tex, references added
arxiv created 1997/12/18 · openalex publication_date 1999/01/25 · arxiv updated 2009/11/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
We present a general formalism for simplifying manipulations of spin indices of massless and massive spinors and vectors in Feynman diagrams. The formalism is based on covariantly reducing the number of field components in the action in favor of chiral or self-dual fields. In this paper we concentrate on calculational simplifications involving fermions in gauge theories by eliminating half of the components of Dirac spinors. Some results are (1) we find reference momenta for massless fermions analogous to those used for external gauge bosons, (2) many of the known supersymmetry identities (tree and one loop) are seen in a simple manner from the graphs, (3) manipulations with external line factors for massive fermions are unnecessary, and (4) some of the simplifications for nearly maximally helicity violating gluonic amplitudes are built into the Feynman rules.