One line header for two line section

Question

In my code I have two line sections. But I want it in 1 line in header . What can I do?

\documentclass{biditufte-handout}
\usepackage{ptext}

\usepackage{fancyhdr}

\pagestyle{fancy}
\fancyhf{}
\fancyhead[L]{\leftmark}
\renewcommand{\headrulewidth}{0pt}

\usepackage{xepersian}
\settextfont{Yas}
\reversemarginpar


\begin{document} 
\section{یک عنوان \\ بخش}
\ptext[1]
\end{document}  

This picture is my goal:

Answer 1

Supply the header as the optional argument

\section[abc def]{abc \\ def}