I'm trying to create a Feynman diagram where a proton and antiproton collide and 2 of their partons create a W boson which then decays leptonically. I made an attempt using the following code:

\feynmandiagram [horizontal=a to b] {
        p1 [particle=\(\overline{p}\), opacity=0] -- [anti fermion] b1 [blob] -- [anti fermion, edge label = \(\overline{u}\)] a,
        p2 [particle=\( p \)] -- [fermion] b2 [blob] -- [fermion, edge label = \(u\)] a,
        a -- [boson, edge label=\(W^{+}\)] b,
        f1 [particle=\(e^{+}\)] -- [fermion] b -- [fermion] f2 [particle=\(\nu_{e}\)],
        p1 -- [opacity=0] p2,

        b1 -- [anti fermion] r11,
        b1 -- [anti fermion] r12,
        r11 -- [fermion, opacity=0] b,
        r12 -- [fermion, opacity=0] b,

        b2 -- [fermion] r21,
        b2 -- [fermion] r22,
        r21 -- [fermion, opacity=0] b,
        r22 -- [fermion, opacity=0] b,

My attempt

However, this doesn't look very nice. First of all, I would like to get both of the incoming protons on the left to have horizontal lines. Secondly, if possible, I would also like the 2 quarks that don't partake in the W production to be horizontal as well (or at least parallel) and equal in length.

I also used some opacity=0 connections to get everything roughly in the correct place. Without these, the diagram looks even less like what I have in mind, but I think it's probably not the way to go since this doesn't result in a nice diagram. How could I solve this using tikz-feynman with compat=1.1.0?

Thanks in advance!

EDIT: Adding a drawing of what i have in mind roughly: enter image description here

EDIT 2: I just noticed that in my latex diagram, there is an up and anti up quark instead of down and anti up, you can ignore that. There's also a mistake with my quark in my own diagram, oops.

1 Answer 1


By using a different way of constructing the diagram, which uses manually placed vertices, I managed to get something that looks like what I was aiming for. It's not a very pretty solution but it does the job (compiled with LuaLaTeX):


        \vertex[blob] (b1) at (0, 0) {};
        \vertex[blob] (b2) at (0,-3) {};
        \vertex (w1) at (1,-1.5);
        \vertex[right = of w1] (w2);
        \vertex[left = of b1] (p1) {$p$};
        \vertex[left = of b2] (p2) {$\overline{p}$};

        \vertex[above right=of w2] (l1) {$\nu_{e} / \nu_{\mu}$};
        \vertex[below right=of w2] (l2) {$e^{+} / \mu^{+}$};

        \vertex (b11) at (0.35, 0.15);
        \vertex (b12) at (0.35, -0.15);
        \vertex (r11) at (1.5, 0.15);
        \vertex (r12) at (1.5, -0.15);

        \vertex (b21) at (0.35, -3 + 0.15);
        \vertex (b22) at (0.35, -3 - 0.15);
        \vertex (r21) at (1.5, -3 + 0.15);
        \vertex (r22) at (1.5, -3 - 0.15);

        \diagram* {
            (p1) -- [fermion] (b1) -- [fermion, edge label = \(d\)] (w1),
            (p2) -- [anti fermion] (b2) -- [anti fermion, edge label' = \(\overline{u}\)] (w1),
            (w1) -- [boson, edge label = \(W^{+}\)] (w2),
            (l2) -- [fermion] (w2) -- [fermion] (l1),
            (b11) -- [fermion] (r11),
            (b12) -- [fermion] (r12),
            (b21) -- [anti fermion] (r21),
            (b22) -- [anti fermion] (r22),


enter image description here

If there are any other suggestions that might be more elegant, you're always welcome to comment them.

  • What is your minimal working example, please? I see only a fragment.
    – Sebastiano
    Apr 7 at 12:00
  • 1
    You're right, I forgot to add the \documentclass{}, \usepackage{} and \begin{document} and \end{document} commands. They've now been added, so it should be compilable now.
    – Viktor VN
    Apr 7 at 13:21
  • What is the font used? No Computer moderm I think.
    – Sebastiano
    Apr 7 at 18:23
  • 2
    It is Arial, because I was using this in a template, but apart from the font, nothing should change if you compile it without any template.
    – Viktor VN
    Apr 7 at 21:15

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