% !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/higgs_pair_pp$TAG.tex
\documentclass[11pt,border=4pt]{standalone}
\usepackage{feynmp-auto}
\usepackage{xcolor}
\definecolor{colkappaV}{rgb}{.15,.75,.15} % kappa_V (green)
\begin{document}
\begin{fmffile}{feyngraph}
  \fmfframe(-7,12)(6,12){ % padding (L,T)(R,B)
  \begin{fmfgraph*}(120,75) % dimensions (WH)
    % line style
    \fmfset{wiggly_len}{12} % boson wavelength
    \fmfset{wiggly_slope}{65} % boson slope of waves
    % external vertices
    \fmfleft{i2,i1}
    \fmfright{o2,h2,h1,o1} % add dummy 'd' for spacing
    \fmfshift{1 up}{h1}
    \fmfshift{1 down}{h2}
    % skeleton
    \fmf{fermion}{i1,v1,o1}
    \fmf{fermion}{i2,v2,o2}
    \fmf{phantom,tension=0.25}{v1,v2} % pull Vqq vertices together
    \fmf{phantom,tension=0.35}{v1,i1,i2,v2} % pull Vqq vertices to left
    \fmffreeze
    % VV -> H -> HH
    \fmf{boson,t=1.8}{v2,v,v1}
    \fmf{dashes}{h1,v}
    \fmf{dashes}{h2,v}
    \fmffreeze
    % Higss coupling
    \fmfv{decor.shape=circle,decor.filled=full,decor.size=4,f=(.15,,.75,,.15),
          l.d=6,l.a=-180,l=\color{colkappaV}$\kappa_{2V}$}{v}
    % labels
    \fmf{phantom,t=2}{w1,v,w2} % create extra vertices for labels
    \fmf{phantom,l.d=2,l.s=right,label=$V$}{v1,w1}
    \fmf{phantom,l.d=2,l.s=left,label=$V$}{v2,w2}
    \fmfv{l.a=158,l.d=6,l=\strut$q$}{i1}
    \fmfv{l.a=-158,l.d=6,l=\strut$q'$}{i2}
    \fmfv{l.a=23,l.d=4,l=h}{h1}
    \fmfv{l.a=-22,l.d=4,l=h}{h2}
    \fmfv{l.a=22,l.d=6,l=\strut$q$}{o1}
    \fmfv{l.a=-22,l.d=6,l=\strut$q'$}{o2}
  \end{fmfgraph*}
  } % close \fmfframe
\end{fmffile}
\end{document}