费曼图与等号对齐

Question

正如问题标题所示，我在对齐三个费曼图时遇到了麻烦。这是我的代码：

\usepackage{tikz}
\usepackage{tikz-feynman}
\usepackage[compat=1.1.0]{tikz-feynman}
\begin{equation}
\feynmandiagram[horizontal=a to b, layered layout]{
a[particle = \(\mu\nu\)] --[photon] b [blob]
};
=
\feynmandiagram[horizontal=a to b, layered layout]{
a[particle = \(\mu\nu\)] --[photon] b [dot]
}; 
+
\feynmandiagram[horizontal=a to b, layered layout]{
a[particle = \(\mu\nu\)] --[photon] b [dot],
b -- [scalar, reversed momentum'=\(\ell\), loop, min distance=2.5cm,rotate = -90] b,
};
\end{equation}

由于加载了许多包，因此您看不到“开始文档”命令或任何内容（但我包含了相关的包）。 以下是上述代码的渲染图：

我还想知道是否有办法使最后的蝌蚪图变得更圆、更小。

提前感谢任何建议或帮助！

Answer 1

您可以使用inline=(a.base)，但您还需要用 修复边界框\strut。

另外，在运算或关系符号周围添加一些额外的间距也是有用的。

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

\begin{document}

\begin{equation}
  \feynmandiagram[inline=(a.base),horizontal=a to b, layered layout]{%
  a[particle = \strut\(\mu\nu\)] -- [photon] b [blob]
  };
\;=
  \feynmandiagram[inline=(a.base),horizontal=a to b, layered layout]{%
  a[particle = \strut\(\mu\nu\)] -- [photon] b [dot]
  };
\;+
  \feynmandiagram[inline=(a.base),horizontal=a to b, layered layout]{%
  a[particle = \strut\(\mu\nu\)] --[photon] b [dot],
  b -- [scalar, reversed momentum'=\(\ell\), loop, 
        min distance=2.5cm,rotate = -90] b,
  };
\end{equation}

\end{document}

Answer 2

我建议您将所有三个图表都包裹在\vcenter{\hbox{...}}原语中。

\documentclass{article} % or some other suitable document class
\usepackage{tikz}
\usepackage[compat=1.1.0]{tikz-feynman}

\begin{document}

\begin{equation}
\vcenter{\hbox{%
  \feynmandiagram[horizontal=a to b, layered layout]{%
  a[particle = \(\mu\nu\)] --[photon] b [blob]
  };}}
=
\vcenter{\hbox{%
  \feynmandiagram[horizontal=a to b, layered layout]{%
  a[particle = \(\mu\nu\)] --[photon] b [dot]
  };}}
+
\vcenter{\hbox{%
  \feynmandiagram[horizontal=a to b, layered layout]{%
  a[particle = \(\mu\nu\)] --[photon] b [dot],
  b -- [scalar, reversed momentum'=\(\ell\), loop, 
        min distance=2.5cm,rotate = -90] b,
  };}}
\end{equation}

\end{document}

Answer 3

\documentclass[preview, border=1cm]{standalone}
\usepackage[compat=1.1.0]{tikz-feynman}
\begin{document}
\begin{equation}
\feynmandiagram[horizontal=a to b, layered layout, baseline]{
a[particle = \(\mu\nu\)] --[photon] b [blob]
};
\quad=\quad
\feynmandiagram[horizontal=a to b, layered layout, baseline]{
a[particle = \(\mu\nu\)] --[photon] b [dot]
}; 
\quad+\quad
\feynmandiagram[horizontal=a to b, layered layout, baseline]{
a[particle = \(\mu\nu\)] --[photon] b [dot],
b -- [scalar, reversed momentum'=\(\ell\), loop, min distance=2.5cm,rotate = -90] b,
};
\end{equation}
\end{document}