我正在尝试在 latexit 中绘制如图所示的费曼图,但目前它什么都没有输出。有人可以帮忙吗?
\documentclass[10pt]{article}
\usepackage[usenames]{color} %used for font color
% !TEX program = pdflatexmk
\usepackage{amssymb} %maths
\usepackage{amsmath} %maths
\usepackage[utf8]{inputenc} %useful to type directly diacritic characters
\usepackage{feynmp-auto}
\begin{document}
\Huge
\begin{fmffile}{feyngraph}
\begin{fmfgraph*}(180,120)
\fmfpen{thick}
\fmfleft{i1,i2}
\fmfv{label=$e^-$,label.distance=10}{i1}
\fmfv{label=$e^+$,label.distance=10}{i2}
\fmfright{o1,o2}
\fmfv{label=$e^+$,label.distance=10}{o2}
\fmfv{label=$e^-$,label.distance=10}{o1}
\fmf{fermion}{i2,a,i1}
\fmf{fermion}{o1,b,o2}
\fmf{photon,label={$A'$}}{a,c}
\fmf{photon,label={$\gamma$}}{c,b}
\end{fmfgraph*}
\end{fmffile}
\end{document}