% !TEX program = pdflatexmk
% !TEX parameter = -shell-escape
% Author: Izaak Neutelings (December 24)
% Instructions: To compile via command line, run the following twice
%   pdflatex -shell-escape extract/singletop$TAG.tex
\documentclass[11pt,border=4pt]{standalone}
\usepackage{feynmp-auto}
\begin{document}
\begin{fmffile}{feyngraph}
  \fmfframe(-8,11)(6,12){ % padding (L,T)(R,B)
  \begin{fmfgraph*}(110,80) % dimensions (WH)
    % line style
    \fmfset{wiggly_len}{12} % boson wavelength
    \fmfset{wiggly_slope}{65} % boson slope of waves
    % external vertices
    \fmfleft{i2,i1}
    \fmfright{o3,o2,o1}
    % main
    \fmf{fermion,t=1.6}{i1,v1}
    \fmf{fermion}{v1,o1}
    \fmf{gluon,t=1.6}{i2,v2}
    \fmf{fermion}{o3,v2}
    \fmf{fermion}{v,o2} % top quark
    \fmf{boson,l.s=left,l.d=1,label=W$^+$\hspace{1pt}}{v,v1} % t-channel
    \fmf{fermion,l.s=left,l.d=-2,label=$\overline{\mathrm{b}}$\hspace{8pt}}{v2,v} % t-channel
    % labels
    \fmfv{l.d=6,l.a=158,l=q}{i1}
    \fmfv{l.d=6,l.a=-152,l=$g$}{i2}
    \fmfv{l.d=6,l.a=22,l=$q'$}{o1}
    \fmfv{l.d=6,l.a=0,l=t}{o2}
    \fmfv{l.d=6,l.a=-20,l=$\overline{\mathrm{b}}$}{o3}
  \end{fmfgraph*}
  } % close \fmfframe
\end{fmffile}
\end{document}