Fig. 12.

Display of candidate $Z(\to \mathit{\mu }\mathit{\mu })$ event (muons in yellow) containing two QCD pile-up jets. Tracks from the primary vertex are in red, those from the pile-up vertex with the highest $\sum p_{\mathrm{T}}^2$ are in green. The top panel shows a transverse and longitudinal view of the detector, while the bottom panel shows the details of the event in the ID in the longitudinal view