There is a package for making Feynman diagrams in LaTeX. Unfortunately, it is
old and dvi latex only. If you are using pdflatex or lualatex, as you should
be, it does not work. Even in regular LaTeX, it’s a bit of a pain. Why is there
not a new package for pdflatex? Turns out, you don’t need one. Due to the
powerful drawing library Tikz, you can create any diagram easily, and can
customize it completely. For example:
