CERN-THESIS-2012-153 26/07/2012 - CERN Document Server

List of Tables
2.1 The fundamental fermions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
2.2 The boson mediators. Note that, the neutral Z-boson is sometimes expressed as Z 0 in different
texts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
2.3 FCNC top quark BR as predicted by several models . . . . . . . . . . . . . . . . . . . . . . . 19
2.4 Present FCNC top quark decays experimental limits . . . . . . . . . . . . . . . . . . . . . . . 20
3.1 LHC beam parameters relevant to the peak luminosity of 10 34 cm −2 s −1 . The quoted geometric
reduction factor assumes a total crossing angle of 285 µrad at the interaction point [61]. . . . 24
3.2 General performance goals of the ATLAS detector. The units for E and pT are in GeV. For
high-pT muons the muon spectrometer performance is independent of the inner-detector system. 28
3.3 Main parameters of the inner detector. The quoted resolutions are typical values. The actual
resolution in each detector is η-dependent [67]. . . . . . . . . . . . . . . . . . . . . . . . . . . 30
3.4 Main parameters of the ATLAS calorimeters [68]. . . . . . . . . . . . . . . . . . . . . . . . . . 31
3.5 Main parameters of the muon spectrometer. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
3.6 BCID-averaged σvis for all algorithms used in ATLAS per vdM scans, and the best estimate
for each algorithm from the combined data, ¯σvis. Errors on σvis per scan are statistical only,
whereas errors on ¯σvis are both statistical and systematic. . . . . . . . . . . . . . . . . . . . 39
4.1 FCNC widths and BR obtained for several coupling values as reported byTopReX for t¯t → bWqZ. 45
5.1 Muon selection requirements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
5.2 Electron selection requirements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
5.3 TL selection requirements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
5.4 Parameters of the b-tagger at the chosen working point, measured in t¯t candidate events in a
MC sample. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
5.5 Data cutflow. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
5.6 ℓ = e,µ. Fraction of events accepted per signal MC sample. The listed uncertainties are
statistical and systematic, respectively. The signal efficiency quoted at the bottom has been
convoluted with the corresponding Z and W BRs. . . . . . . . . . . . . . . . . . . . . . . . . 70
6.1 Predicted number of fake background events per jet multiplicity. The signal region background
prediction corresponds to ≥2 jets. The listed uncertainties are statistical and systematic,
respectively. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
6.2 Expected backgrounds in the 2ID+TL analysis and the number of events observed in the data
at the pre-selection level. Both statistical and systematic uncertainties are included. . . . . . 79
6.3 Expected backgrounds in the 2ID+TL analysis and the number of events observed in the data
at the final selection level. Both statistical and systematic uncertainties are included. . . . . . 79
6.4 Number of selected data events, expected number of background events (ZZ, WZ and t¯tW/Z
events estimated from Monte Carlo simulation samples and the DD estimations for 1 and 2+3
fake leptons) and the estimated signal efficiency (multiplied by the corresponding W and Z
bosons’ BRs), after the event final selection. The corresponding statistical uncertainties are
also shown. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80
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