TikZ-Feyman help with a particular Diagram

Question

Hello i am trying to make a Feynman diagram with this code

\bigskip
\begin{figure}[H]
\centering
\tikzfeynmanset{
every vertex={red, dot},
every particle={blue},
every blob={draw=green!40!black, pattern color=green!40!black},
}
\feynmandiagram [horizontal=a to b] {
a [particle={\(\gamma, Z\)}] -- [fermion] b [blob],
c -- [fermion] b -- [fermion] d,
};,
\caption{\label{fig:firstmesonimag} A $\pi^0$ decaying onto two gammas.}
\end{figure}

and i want to make something like this

Can anyone help how to get the double fermion horizontally along with the incoming nucleus?

Any help will greatly appreciated.

Thanks!

Answer 1

\documentclass{article}
\usepackage{amsmath}
\usepackage{tikz-feynman}
\begin{document}

\begin{tikzpicture}
  \feynmandiagram [horizontal=a to d] {
    a -- [fermion,edge label=$N$] b [dot] -- [double,with arrow=0.5,edge label=$\mathcal{R}$] c -- [fermion,edge label=$N'$] d,
    i -- [charged boson,edge label=$W^i$] b,
    c -- [charged scalar,edge label=$\pi$] o,
  };
\end{tikzpicture}

\end{document}