4

My Wick contractions aren't displaying properly: the ones on the left are fine but the ones on the right have the contraction at a very low height

\documentclass[amsmath,amssymb,12pt,eqsecnum]{revtex4}
\usepackage[a4paper]{geometry}
\linespread{1}
\usepackage[breaklinks, colorlinks, citecolor=blue]{hyperref}
\usepackage{slashed}
\usepackage{gensymb}
\usepackage{simplewick}
\usepackage{feynmp-auto}
\usepackage[pdftex]{graphicx}
\begin{document}

\begin{eqnarray}
        \contraction{}{\psi}{|p}{,} \psi |p,s \rangle = u^s (p) &\quad& \langle 
        p \contraction{}{,}{s|}{\bar{\psi}} ,s|\bar{\psi} 
        = \bar{u}^s (p) \\ \nonumber
        \contraction{}{\bar{\psi}}{|k}{,} \bar{\psi}|k,s \rangle = \bar{v}^s (k) 
        &\quad& \langle k \contraction{}{,}{s|}{\psi} ,s| \psi 
        = v^s (k) \nonumber
\end{eqnarray}

\end{document}
  • 1
    Never use eqnarray; in this case the align* environment is what you want. – egreg Dec 28 '14 at 10:38
6

simplewick uses the height of the character in the second argument to raise the contraction symbol to its appropriate height. Unfortunately , is a little too small so you have to add \vphantom{...} to raise the symbol a more reasonable height.

\documentclass{article}
\usepackage{simplewick}
\begin{document}
\begin{eqnarray}
  \contraction{}{\psi}{|p}{,} \psi |p,s \rangle = u^s (p) &\quad& \langle 
  p \contraction{}{\vphantom{\bar\psi},}{s|}{\bar{\psi}} ,s|\bar{\psi} 
  = \bar{u}^s (p) \\ \nonumber
  \contraction{}{\bar{\psi}}{|k}{,} \bar{\psi}|k,s \rangle = \bar{v}^s (k) 
  &\quad& \langle k \contraction{}{\vphantom{\psi},}{s|}{\psi} ,s| \psi 
  = v^s (k) \nonumber
\end{eqnarray}
\end{document}

enter image description here

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