Measurement of the Z boson cross-section in - Harvard University ...

Chapter 8: Properties of Z bosons and measurement of Z → µµ cross-section 225
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dt = 331 nb
Data 2010( s = 7 TeV)
Z → µ µ
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MDT hits/track
Figure 8.1: MDT hits per muon track for signal Monte Carlo and data after the full
Z selection.
Hit distributions
Figure 8.1 shows the number of MDT hits per track. Unlike the corresponding plot
at the preselection level (Figure 6.2), we no longer see tracks with less than 6 MDT
hits. However, in spite of the large statistical uncertainty, we note the systematic
migration of the data distribution to lower hit bins in the peak region, which we
recognize as an effect of misalignment.
Figure 8.2 shows the number of RPC η and φ hits per track, where we see good
data-Monte Carlo agreement. Figure 8.3 shows the TGC η and φ hit distributions.
As in Figure 6.4 at the preselection stage, the effect of cross-talk shows up as several
data bins being higher than corresponding Monte Carlo bins.
Figure 8.4 shows the number of Pixel hits on the inner detector track associated