
\documentclass[border=5pt,multi=true]{standalone}
\usepackage{standalone}
\usepackage{ifthen}
\usepackage{microtype}
\usepackage{lineno}
\usepackage{xspace}
\usepackage{caption}
\usepackage{graphicx}
\usepackage{subcaption}
\usepackage{placeins}
\usepackage{rotating}
\usepackage{color}
\usepackage{colortbl}
\usepackage{booktabs}
\usepackage{multirow}
\usepackage{adjustbox}
\usepackage{feynmp}
\usepackage{lipsum}
\usepackage{amsmath}
\usepackage{amssymb}
\usepackage{amsfonts}
\usepackage{upgreek}
\usepackage{mathtools}
\usepackage{hyperref}
\usepackage{hypcap}
\usepackage{cite}
\usepackage{mciteplus}
\usepackage{tikz}
\usepackage{makecell}
\usepackage{longtable}

\begin{document}
  
    \begin{tabular}{l r@{$\,\pm\,$}l r@{$\,\pm\,$}l r@{$\,\pm\,$}l}
      & \multicolumn{2}{l}{} & \multicolumn{2}{l}{Mistag} & \multicolumn{2}{l}{Combinatorial} \\
      Mode & \multicolumn{2}{l}{Signal yield} & \multicolumn{2}{l}{background [\%]} & \multicolumn{2}{l}{background [\%]} \\
      \midrule
       $ D\xspace\xspace^0\xspace\!\rightarrow\xspace  K\xspace\xspace^0_{\rm\scriptscriptstyle S}\xspace K\xspace\xspace^-\xspace\pi\xspace\xspace^+\xspace\xspace$ \xspace & 113\,290 & 130 & 0.89 & 0.09 & 3.04 & 0.14 \\
       $ D\xspace\xspace^0\xspace\!\rightarrow\xspace  K\xspace\xspace^0_{\rm\scriptscriptstyle S}\xspace K\xspace\xspace^+\xspace\pi\xspace\xspace^-\xspace\xspace$ \xspace & 76\,380 & 120 & 1.93 & 0.16 & 2.18 & 0.15 \\
    \end{tabular}
  
  
\end{document}
