% !TEX program = pdflatexmk
% !TEX parameter = -shell-escape
% Author: Izaak Neutelings (September 24)
% Instructions: To compile via command line, run the following twice
%   pdflatex -shell-escape extract/ttbar$TAG.tex
\documentclass[11pt,border=4pt]{standalone}
\usepackage{feynmp-auto}
\begin{document}
\begin{fmffile}{feyngraph}
  \fmfframe(-8,15)(15,18){ % padding (L,T)(R,B)
  \begin{fmfgraph*}(120,75) % dimensions (WH)
    % line style
    \fmfset{wiggly_len}{12} % boson wavelength
    \fmfset{wiggly_slope}{65} % boson slope of waves
    % external vertices
    \fmfleft{i2,i1}
    \fmfright{o2,o,o1}
    \fmfshift{2 up}{o}
    \fmfshift{6 right}{o}
    % main
    \fmf{fermion}{i1,v1,i2}
    \fmf{gluon,label=$g$,label.side=right,label.dist=10}{v2,v1}
    \fmf{phantom}{o2,v2,o1}
    \fmffreeze
    \fmf{fermion}{o2,v2,v,o1}
    \fmf{gluon,t=0}{v,o}
    % labels
    \fmflabel{$q$}{i1}
    \fmflabel{$\overline{q}$}{i2}
    \fmflabel{$\overline{\mathrm{t}}$}{o2}
    \fmflabel{t}{o1}
    \fmflabel{$g$}{o}
    %\fmfv{decor.shape=circle,decor.filled=full,decor.size=3.5,f=(.7,,.1,,.1)}{v}
  \end{fmfgraph*}
  } % close \fmfframe
\end{fmffile}
\end{document}