# Feynmf — Two loop correction

How to draw a two (or even more) loop diagrams using Feynmf?

I tried

\documentclass{article}
\usepackage{feynmp}
\begin{document}
\unitlength = 1mm
\begin{fmffile}{twoloop}
\begin{fmfgraph}(100,60)
\fmfleft{i}
\fmfright{o}
\fmf{fermion}{i,v1,o}
\fmf{fermion}{v1,v2,v1}
\fmf{fermion}{v2,v2}
\end{fmfgraph}
\end{fmffile}
\end{document}


but it didn't work.

I plotted it using LaTeXit. The one loop diagram worked just fine so I guess it's the problem with my usage of Feynmf.

• Could you please make a full compilable example? – egreg Feb 15 '14 at 21:50

I have been able to solve this in a fashion:

\begin{fmfgraph*}(120,75)
\fmfleft{i1,i2,i3}
\fmfright{o1,o2,o3}
\fmf{plain}{i1,v1,o1}
\fmffreeze
\fmf{phantom}{i2,v2,o2}
\fmf{phantom}{i3,v3,o3}
\fmf{plain,left}{v1,v2,v1}
\fmf{plain,left}{v2,v3,v2}
\fmfdot{v1,v2}
\end{fmfgraph*}


This produces circles instead of egg shaped loops, and differently sized ones at that. I suppose one can fix the sizes, I'll update if I manage to get to that.