Fig. 11.

Efficiency to reconstruct and then select the hard-scatter primary vertex as a function of the average number of pp interactions per bunch crossing, $\mathit{\mu }$, for different physics processes: a all reconstructed events; b events with at least two muons with $p_{\text{T}}>15$ GeV reconstructed within the ATLAS inner detector acceptance. The points showing the $t\overline{t}$ efficiency with and without acceptance criteria overlap