\begin{picture}(420,60)(0,0)
\SetColor{Black}
%\Text(0,110)[l]{$(a)$}
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\Vertex(50,10){1.8}
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\Line(50,50)(90,60)
\Gluon(50,10)(90,0){-2.5}{4}
\Line(50,10)(90,0)
%\Text(120,110)[l]{$(b)$}
\Vertex(145,30){1.8}
\Gluon(145,30)(175,30){3}{3}
\Vertex(175,30){1.8}
\Gluon(120,60)(145,30){3}{4}
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\Line(200,60)(175,30)
\Gluon(175,30)(200,0){-2.5}{4}
\Line(175,30)(200,0)
%\Text(0,30)[l]{$(c)$}
\Vertex(255,30){1.8}
\Gluon(255,30)(285,30){3}{3}
\Vertex(285,30){1.8}
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\Gluon(310,60)(285,30){-2.5}{4}
\Line(310,0)(285,30)
\Gluon(310,0)(285,30){2.5}{4}
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%\Text(120,30)[l]{$(d)$}
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\Gluon(420,0)(380,10){2.5}{4}
\ArrowLine(380,10)(340,0)
\ArrowLine(340,60)(380,50)
%\Text(150,30)[l]{$\tilde{q}_{1,2}$}
\end{picture}