Getting Started with FeynMF Package: Issues and Solutions

[TriTertButoxy]

Hi I'm getting used to the FeynMF package used to draw Feynman Diagrams in LaTeX, and the hard work of learning to use the package has paid off.

However, there are a couple issues that I'm having with the package.

1. Labels don't appear even when I use the \fmflabel command or the l=blah option in the \fmf{fermion, l=$q$}{i1,v1,o2} command inside the fmfgraph* environment. I know that to force the previewer to update a diagram, I must delete the .pk file associated with the diagram. But the labels don't show up, even though the rest of the diagram refreshes after the procedure.

2. How do I get miniature arrows beside the external legs and propagators to indicate direction of momentum? The arrows in the diagrams indicate flow of charge, and I want to be able to make this distinction. Note that this was done in Peskin and Shroder's Introduction to Quantum Field Theory, so it's not impossible.

Any suggetions would be appreciated.

Thanks!

 

[TriTertButoxy]

Also, I've noticed that if I include the feynmp package instead of the feynmf package, all diagrams vanish. Why is that happening?

It's a little frustrating .

 

[ravenprp]

Hi there,

Glad to hear that you're getting the hang of using the FeynMF package for Feynman Diagrams in LaTeX! It can definitely be a bit tricky to learn, but it's worth it in the end.

In regards to your first issue with labels not appearing, it sounds like you may be missing a step in the process of updating the diagram. In addition to deleting the .pk file, you also need to run the command "latex filename" in your terminal or command prompt. This will update the .dvi file, which is what the previewer reads. Make sure to do this after deleting the .pk file, and your labels should appear.

For your second issue, adding arrows to indicate direction of momentum is possible with the FeynMF package. You can use the command \fmf{fermion,arrow=half,arrow_len=5}{i1,v1} to add a half arrow to the fermion line from point i1 to v1. You can adjust the arrow length as needed. Similar commands can be used for other types of lines (e.g. \fmf{photon,arrow=full} for a full arrow on a photon line). Refer to the FeynMF manual for more information on these commands.

I hope this helps! Don't hesitate to reach out if you have any further questions or issues. Happy diagramming!