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\begin{document}
\begin{tabular}{ccc}
    \hline
    \hline  \\
    Source & $\mathcal{R}_{\kern 0.2em\overline{\kern -0.2em  D\xspace}{}\xspace{}^0\xspace  K\xspace\xspace^+\xspace K\xspace\xspace^-\xspace/\kern 0.2em\overline{\kern -0.2em  D\xspace}{}\xspace{}^0\xspace \pi\xspace\xspace^+\xspace\pi\xspace\xspace^-\xspace}$ & $\mathcal{R}_{ B\xspace\xspace^0_ s\xspace\xspace\xspace/ B\xspace\xspace^0\xspace}$  \\
    \hline  \\
    HW trigger efficiency & 2.0  & $-$\\
    PID efficiency  & 2.0 & $-$ \\
    PDF modelling & 3.2 & 4.5\\
    $f_s/f_d$ & $-$ & 5.8 \\
    \hline  \\
    Total & 4.3 & 7.3 \\
    \hline
\end{tabular}
\end{document}
