There have been several packages to draw Feynman diagrams in tex environment.
But I have used two:
Axodraw ( Jaxodraw)
Feynmf (Feynmp)
However, one is rather old and non-standard and the other is not easy to use.
New package "Tikz-Feynman" seems to be good in look and easy in usage.
However, when I try to use the package the diagrams are weird and different shapes
from examples.
The problem was that I compiled them with 'pdflatex'.
It looks like the "Tikz-Feynman" is only compatible with 'lualatex'.
Since it is not written in the manual or webpage, it was difficult to know.
On the other hand, I found each package have advantage and disadvantage.
It is mostly how the vertices are positioned by the command.
For me, Feynmf seems to be better than others. But, because it use metafont,
it is rather slow and I have problem with TexStudio using Feynmf.
(I had to delete metafont whenever I modify them).
