XeTeX ⇒ How to get a sans-serif math wide hat in {xe|lua}latex?

[user49915]

Feeding

Code: Select all

\documentclass{standalone}
\usepackage{unicode-math}
\begin{document}
\(\widehat{\strut~~~\,\,\,\ \ \ \mskip10mu\mkern10mu\strut}\)

\(\mathsf{\widehat{\strut~~~\,\,\,\ \ \ \mskip10mu\mkern10mu\strut}}\)
\end{document}

to xelatex produces

file.xelatex.png (1.28 KiB) Viewed 13593 times

and feeding it to lualatex results in

file.lualatex.png (1.27 KiB) Viewed 13593 times

As you notice, the sans-serif hat is narrow in both cases whatever junk you put inside. How to produce a wide hat (without anything under it) in the scope of \mathsf{...}? Here, we don't really want an accent, but only a decently wide hat (say, 1em) as a symbol in a sans-serif math font.

Crosspost: http://tex.stackexchange.com/questions/ ... xelualatex