# Drawing tadpole diagram using feynmp

I have a basic question, how can I draw a tadpole using feynmp?

## 1 Answer

Here is one way. You need run latex on this twice to get the output. I obtained this by following the types of examples given at http://osksn2.hep.sci.osaka-u.ac.jp/~taku/osx/feynmp.html

\documentclass{article}

\usepackage{feynmp-auto}

\begin{document}
\unitlength=1mm

\begin{fmffile}{example}
\begin{fmfgraph}(40,25)
\fmfleft{i}
\fmfright{o}
\fmf{photon}{i,v1}
\fmf{plain,left}{v1,o,v1}
\end{fmfgraph}
\end{fmffile}

\end{document}