
\begin{tikzpicture}
\begin{feynman}
\vertex (a);
\vertex [left=4cm of a] (b);
\vertex [above right=3.5cm and 2.5cm of a] (c);
\vertex [above right=1cm and 4cm of a] (d);
\vertex [right=4cm of a] (e);
\vertex [below right=2cm and 4cm of a] (f);
\diagram*{
(b)--[thick,fermion,edge label={$e^-(E,\vec p, 0)$}] (a),
(a) --[thick,boson,edge label={\small $\gamma(k,\vec k, \alpha_c)$}] (c),
(a)--[thick,fermion,edge label'={$e^{-^\prime}(E^\prime,\vec p^\prime, \theta_c)$}] (d),
(a) --[thick,boson,edge label'={\small $\gamma^\prime(k^\prime,\vec k^\prime, \theta_\gamma)$}] (f),
};
\end{feynman}
\end{tikzpicture}