English

Dirac and Majorana Feynman Rules with four-fermions

High Energy Physics - Phenomenology 2018-03-02 v2 High Energy Physics - Theory

Abstract

A compact method for amplitude calculations in theories with Dirac and Majorana effective operators is discussed. Using the renormalizable formalism of Denner et al., [1,2] for propagators, vertices and fermion (number) flow and introducing new "reading-rules", it is shown that fermions can be treated as scalars in the diagrams. The effect of Fermi-statistics appears only in overall signs and is determined once for whole classes of diagrams. Each vertex in this method corresponds to two or more vertices in the standard treatment of effective theories. As such, the advantages of this approach grow together with the number of four-fermion vertices in a given diagram. The discussion develops around effective field theories based on the Standard Model, up to four-fermions and to any order in perturbation theory. Even so, the framework is more general and can be applied elsewhere.

Keywords

Cite

@article{arxiv.1802.02657,
  title  = {Dirac and Majorana Feynman Rules with four-fermions},
  author = {Michael Paraskevas},
  journal= {arXiv preprint arXiv:1802.02657},
  year   = {2018}
}

Comments

22 pages, 2 figures. v2: Few minors, prepared for journal submission

R2 v1 2026-06-23T00:15:10.212Z