How to include contraction symbols in LaTeX

by nrqed
Tags: contraction, include, latex, symbols
 Sci Advisor HW Helper P: 3,025 I apologize, I know this is not a QM question per se but I think I am more likely to find someone who could answer this here. I'd like to know (or rather, be reminded of) how to draw contraction symbols in LaTeX (or TeX). I mean the symbol we use to show how two fields are "paired up" when we do perturbation theory in QFT. You know what I mean: a line that goes a bit down (or up) from a field, runs across horizontally to the second field and then goes up again (or down again). I used to have a way to do that but when my work computer was upgraded I lost those files. Thanks in advance. Patrick
 P: 527 For that I use the package simplewick.sty, available here: http://www.ctan.org/tex-archive/macr...ib/simplewick/
 P: 6 \contraction works fine for me with simplewick.sty, placing the style file in the same same directory should work. Perhaps you forgot \usepackage. This example is compilable: \documentclass{article} \usepackage{simplewick} \begin{document} $\contraction[2ex]{}{\phi_1}{\phi_2\phi_3}{\phi_4}$ \end{document} Stefan