# Trying to create a mid vtx with two fermions (Tiks-Feynman)

So i've been working hard over the past 7 hrs and I am at the point where Tiks-Feynman needs improvement or I just don't get it. This is most likely my 4th question in this forum and I feel real embarrassed.

I need to complete three Feynman diagrams to include in my thesis and so far I haven't been very successful although the learning curve is not too steep.

Here is the code I have so far:

 \resizebox{0.5\textwidth}{!}{%
\feynmandiagram [ horizontal=a to t1,baseline=(a4.base)] {
a  -- [fermion, edge label'={$N$}] t1 [dot] , t1 -- t2 , t1 -- t3 ,t1 --
[fermion, edge label'={$N$}] t4,
};
}


and these is what i got:

And i need to draw these three feynman diagrams as they are, include [dots]:

Any help on how to draw these diagrams will be appreciated by me and the community (I'm sure)....

All these diagrams are somewhat hard to obtain with layout mechanism provided by the packages, but very easy done without those algorithms.

\documentclass[a4paper]{article}
\usepackage{tikz-feynman}
\tikzfeynmanset{compat=1.1.0}
\begin{document}

\begin{tikzpicture}[line width=.7pt]
\begin{feynman}
\vertex (a);
\vertex[right=2.5cm of a](b);
\vertex[right=2.5cm of b](c);
\vertex[above=1.5cm of a](d);
\vertex[above=1.5cm of c](e);
\diagram*{
(a)  -- [fermion,edge label'={$N$}] (b) -- [fermion,edge
label'={$N$}] (c),
(d) -- [charged boson,edge label={$W^i$}] (b) --
[charged scalar,edge label={$\pi$}] (e)
};
\draw[fill=black] (b) circle (2pt);
\end{feynman}
\begin{feynman}[yshift=-3cm]
\vertex (a);
\vertex[right=2.5cm of a](b);
\vertex[right=2.5cm of b](c);
\vertex[above=1.5cm of a](d);
\vertex[above=1.5cm of c](e);
\path (d)--(b) coordinate[midway](f);
\diagram*{
(a)  -- [fermion,edge label'={$N$}] (b) -- [fermion,edge
label'={$N$}] (c),
(d) -- [charged boson,edge label={$W^i$}] (f) --
[charged scalar,edge label={$\pi$}] (b) --
[charged scalar,edge label={$\pi$}] (e)
};
\draw[fill=black] (f) circle (2pt);
\end{feynman}
\begin{feynman}[yshift=-6cm]
\vertex (a);
\vertex[right=2.5cm of a](b);
\vertex[right=2.5cm of b](c);
\vertex[above=1.5cm of a,xshift=2cm](d);
\vertex[above=1.5cm of c](e);
\path (b)--(e) coordinate[midway](f);
\diagram*{
(a)  -- [fermion,edge label'={$N$}] (b) -- [fermion,edge
label'={$N$}] (c),(b) --
[charged scalar,edge label={$\pi$}] (f)
--  [charged scalar,edge label={$\pi$}] (e),
(d) -- [charged boson,edge label={$W^i$}] (f)
};
\draw[fill=black] (f) circle (2pt);
\end{feynman}
\end{tikzpicture}
\end{document}