"Figure 6a" of "Search for vector-like leptons coupling to first- and second-generation Standard Model leptons in $pp$ collisions at $\sqrt{s}=13$ TeV with the ATLAS detector"

Comparison between data and the background prediction for the event yields in the (a) 10 VLLe SRs, (b) 10 VLLμ SRs, and (c) 9 CRs, after a background-only fit to data (`post-fit') in the (a) VLLe SRs and CRs and (b, c) VLLμ SRs and CRs. The background contributions in the CRs after the likelihood fit to data in the VLLe SRs and CRs are comparable to those in (c). Distributions for the VLLeD and VLLμD signal points for a VLL mass of 600 GeV are overlaid for comparison in (a) and (b), respectively. The lower panels show the ratio of data to the background estimate (`B.'), separately for post-fit background (black points) and pre-fit background (dashed blue line). The size of the combined statistical and systematic uncertainty in the background prediction is indicated by the blue hatched band.