Majoranized Feynman rules

TL;DR

This paper clarifies that the compact Feynman rules for Majorana fermions are essentially a phase convention for spinors, applicable to both Majorana and Dirac fermions, and relates this to standard spinor techniques.

Contribution

It demonstrates that the proposed Feynman rules are a phase convention and connects this with common spinor phase conventions, clarifying their applicability.

Findings

Feynman rules are a phase convention for spinors

The phase convention applies to both Majorana and Dirac fermions

Relation established between the Feynman rules and standard spinor techniques

Abstract

We point out that the compact Feynman rules for Majorana fermions proposed by Denner et al. are in fact a convention for the complex phases of (anti)spinors, valid for both Majorana and Dirac fermions. We establish the relation of this phase convention with that common in the use of spinor techniques.