How to put a hat on a binary operator and maintain spacing

Question

This is maybe easy question. How is the right/good way to put a hat on a binary operator like \otimes? For example a\otimes b vs a\hat\otimes b In the second case it is not typeset as a binary operator anymore, i.e. missing spaces.

Answer 1

Use a\mathbin{\hat\otimes}b to retrieve the original spacing of a binary operator:

\documentclass{article}
\begin{document}
$a\otimes b \quad a\hat\otimes b \quad a\mathbin{\hat\otimes}b$
\end{document}​