Drawing Feynman diagrams

A Feynman diagram is a mathematical visualization of the behavior of subatomic particles. There are several ways to generate them using LaTeX.

How to do it...

We will use the tikz-feynman package. The author documented it in J. Ellis, ‘TikZ-Feynman: Feynman diagrams with TikZ’, (2016), arXiv:1601.05437 [hep-ph], and you can access the documentation executing texdoc tikz-feynman via the command line or at https://texdoc.org/pkg/tikz-feynman.

The positions of the vertices are calculated using Lua, so we must compile with LuaLaTeX. Follow these steps:

1. Start with any document class:

   \documentclass[border=10pt]{standalone}

2. Load the tikz-feynman package:

   \usepackage{tikz-feynman}

3. Load additional useful TikZ libraries and begin the document:

   \usetikzlibrary{positioning,quotes}
   \begin{document}

4. Utilize the \feynmandiagram command as follows:

   \feynmandiagram [horizontal=a to b] {
     i1 [particle=$e^-$] -- [fermion] a
   ...