Tikz-Feynman：一条费米子线上的多个箭头和对齐（0vββ）

Question

我正在尝试对齐 0vββ 图中夸克箭头：

因此，我希望在 4 条“未修改”的夸克线上各有 2 个箭头：第一个箭头应与相互作用的下夸克箭头水平对齐（这样它就位于 d 夸克箭头的正上方）。第二个箭头也一样，它应该位于传出上夸克箭头的正上方。

基本上就像这里左图那样：

所以我的问题是

1）如何在一条费米子线上得到两个箭头

2）如何正确对齐箭头？

（3）另外，我们可以将马约拉纳中微子的标签稍微向左移动一点吗？）

在手册中没有找到任何内容。

这是我的代码：

\documentclass[convert]{standalone}

\usepackage[compat=1.1.0]{tikz-feynman}

\begin{document}

\begin{tikzpicture}
\begin{feynman}
\vertex (b);
\vertex [below=of b] (c);
\vertex [below left=1cm and 1.4cm of c] (d);
\vertex [above left=1cm and 1.4cm of b] (a);
\vertex [left=of a] (i1) {d};
\vertex [left=of d] (i2) {d};
\vertex[right = 2cm of b] (f2) { \(e^{-}\)};
\vertex[right = 2cm of c] (f3) { \(e^{-}\)};
\vertex[below = 2cm of f3] (f4) {u};

\vertex[above = 2cm of f2] (f1) {u};

\vertex[above=0.35cm of i1] (f6) {d}; % d quark outgoing
\vertex[above=0.35cm of f1] (i3) {d}; % d quark ingoing

\vertex[above=0.35cm of i3] (f7) {u}; % u quark outgoing
\vertex[above=0.35cm of f6] (i4) {u}; % u quark ingoing

% copy quarks for bottom

\vertex[below=0.35cm of i2] (f8) {d}; % d quark outgoing
\vertex[below=0.35cm of f4] (i5) {d}; % d quark ingoing

\vertex[below=0.35cm of i5] (f9) {u}; % u quark outgoing
\vertex[below=0.35cm of f8] (i6) {u}; % u quark ingoing


\diagram* {
    (a) -- [boson, edge label'=\(W^{-}\)] (b) -- [anti majorana, insertion=0.5, edge label' = \(\nu_{M}\) ] (c) -- [boson, edge label'=\(W^{-}\)] (d),
    (i1) -- [fermion] (a),
    (i2) -- [fermion] (d),
    (a) -- [fermion] (f1),
    (b) -- [fermion] (f2),
    (c) -- [fermion] (f3),
    (d) -- [fermion] (f4),
    (f6) -- [fermion, out=0, in=200] (i3),
    (i4) -- [fermion, out=0, in=200] (f7),
    (f8) -- [fermion, out=0, in=160] (i5),
    (i6) -- [fermion, out=0, in=160] (f9),
};

\draw [decoration = {brace} , decorate] (i1.south west) -- (i4.north west) node [pos = 0.5 , left = 0.125cm] {\huge n};

\draw [decoration = {brace} , decorate] (f7.north east) -- (f1.south east) node [pos = 0.5 , right = 0.125cm] {\huge p};

\draw [decoration = {brace} , decorate] (i6.south west) -- (i2.north west) node [pos = 0.5 , left = 0.125cm] {\huge n};

\draw [decoration = {brace} , decorate] (f4.north east) -- (f9.south east) node [pos = 0.5 , right = 0.125cm] {\huge p};

\end{feynman}
\end{tikzpicture}
\end{document}

非常感谢！ ：）

Answer 1

费米子、马约拉纳和带电玻色子风格实际上都使用内部（且未记录）with arrow风格。我没有公开该with arrow风格，因为我最初没有想到会需要它，但我认为我会在下一版 Ti 中公开它钾Z-费曼。

with arrow和样式with reversed arrow在指定位置沿路径放置箭头或反向箭头。可以通过以下方式指定位置：

• 0 到 1 之间的数字：这表示在路径上放置箭头的位置，0 对应起点，0.5 对应中点，1 对应终点；
• 正距离：箭头放置在路径下给定距离处；
• 负距离：箭头放置在距路径末端给定距离的位置。

因为在您的例子中，我们希望箭头对齐，所以我实际上定义了两个临时命令来保存距离、\tmpda和\tmpdb，并将它们用作的参数with arrow。这样就避免了必须手动调整每个距离。

\documentclass[tikz]{standalone}

\usepackage[compat=1.1.0]{tikz-feynman}

\begin{document}

\begin{tikzpicture}
  \begin{feynman}
    \vertex (b);
    \vertex [below=of b] (c);
    \vertex [below left=1cm and 1.4cm of c] (d);
    \vertex [above left=1cm and 1.4cm of b] (a);
    \vertex [left=of a] (i1) {d};
    \vertex [left=of d] (i2) {d};
    \vertex [right = 2cm of b] (f2) {\(e^{-}\)};
    \vertex [right = 2cm of c] (f3) {\(e^{-}\)};
    \vertex [below = 2cm of f3] (f4) {u};

    \vertex [above = 2cm of f2] (f1) {u};

    \vertex [above=0.35cm of i1] (f6) {d}; % d quark outgoing
    \vertex [above=0.35cm of f1] (i3) {d}; % d quark ingoing

    \vertex [above=0.35cm of i3] (f7) {u}; % u quark outgoing
    \vertex [above=0.35cm of f6] (i4) {u}; % u quark ingoing

    % copy quarks for bottom

    \vertex [below=0.35cm of i2] (f8) {d}; % d quark outgoing
    \vertex [below=0.35cm of f4] (i5) {d}; % d quark ingoing

    \vertex [below=0.35cm of i5] (f9) {u}; % u quark outgoing
    \vertex [below=0.35cm of f8] (i6) {u}; % u quark ingoing

    \newcommand\tmpda{0.7cm}
    \newcommand\tmpdb{-1.7cm}
    \diagram* {
      (a) -- [boson, edge label'=\(W^{-}\)] (b) -- [anti majorana, insertion=0.5, edge label' = \(\nu_{M}\) ] (c) -- [boson, edge label'=\(W^{-}\)] (d),
      (i1) -- [with arrow=\tmpda] (a),
      (i2) -- [with arrow=\tmpda] (d),
      (a) -- [with arrow=\tmpdb] (f1),
      (b) -- [fermion] (f2),
      (c) -- [fermion] (f3),
      (d) -- [with arrow=\tmpdb] (f4),
      (f6) -- [with arrow=\tmpda, with arrow=\tmpdb, out=0, in=200] (i3),
      (i4) -- [with arrow=\tmpda, with arrow=\tmpdb, out=0, in=200] (f7),
      (f8) -- [with arrow=\tmpda, with arrow=\tmpdb, out=0, in=160] (i5),
      (i6) -- [with arrow=\tmpda, with arrow=\tmpdb, out=0, in=160] (f9),
    };

    \draw [decoration = {brace} , decorate] (i1.south west) -- (i4.north west) node [pos = 0.5 , left = 0.125cm] {\huge n};

    \draw [decoration = {brace} , decorate] (f7.north east) -- (f1.south east) node [pos = 0.5 , right = 0.125cm] {\huge p};

    \draw [decoration = {brace} , decorate] (i6.south west) -- (i2.north west) node [pos = 0.5 , left = 0.125cm] {\huge n};

    \draw [decoration = {brace} , decorate] (f4.north east) -- (f9.south east) node [pos = 0.5 , right = 0.125cm] {\huge p};

  \end{feynman}
\end{tikzpicture}
\end{document}

希望这能有所帮助！另外，图表也很棒！很高兴看到 Ti钾正在使用 Z-Feynman :)