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

More documents

Recommendations

Info

6.2.3 Summary The yields of the expected background and the data observation, as quoted in Section 5.6.1, for the preselection and the final selection are presented in Table 6.2 and Table 6.3, respectively. In both stages of the selection, the observed signal candidates are consistent with the number of background events expected. 6.3 Backgrounds to the 3ID Analysis A complete description of the evaluation of backgrounds to the 3ID analysis is presented in Appendix B and in Reference [8]. # jets 2ID + fake TL prediction 2 4.1 ± 1.4 ± 0.8 3 2.1 ± 0.8 ± 0.4 4 0.9 ± 0.3 ± 0.2 ≥ 5 0.4 ± 0.1 ± 0.1 ≥ 2 7.6 ± 1.6 ± 1.5 Table 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. 2ID+TL Preselection ZZ and WZ 1.9 + − 0.9 1.0 t¯tW and t¯tZ 0.9 ±0.2 fakes 23.7 ±4.8 expected background <strong>26</strong>.5 ±4.9 data 28 Table 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. 2ID + TL Final Selection ZZ and WZ 1.0 + − 0.5 0.6 t¯tW and t¯tZ 0.25 ±0.05 fakes 7.6 ±2.2 expected background 8.9 ±2.3 data 8 Table 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
3ID Final Selection ZZ and WZ 9.5 ±4.4 t¯tW and t¯tZ 0.51 ±0.14 t¯t, WW 0.<strong>07</strong> ±0.02 Z+jets 1.7 ±0.7 Single-top 0.01 ±0.01 2+3 fake leptons 0.0 + − 0.2 0.0 expected background 11.8 ±4.4 data 8 Table 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. 6.3.1 Summary The yields of the expected background and the data observation for the final selection of the 3ID selection are presented in Table 6.4. The number of signal candidates in data are consistent with the expected background within one sigma. 80
Page 1 and 2:
CERN-THESIS-2012-153 26/07/2012 c
Page 3 and 4:
Abstract A search for flavor-changi
Page 5 and 6:
Acknowledgments I first want to tha
Page 7 and 8:
Table of Contents List of Tables .
Page 9 and 10:
List of Tables 2.1 The fundamental
Page 11 and 12:
List of Figures 2.1 The potential V
Page 13 and 14:
5.15 Distributions of the 3ID analy
Page 15 and 16:
This thesis is organized as follows
Page 17 and 18:
the question whether each neutrino
Page 19 and 20:
gauge invariant field strength tens
Page 21 and 22:
for strong interactions. Although W
Page 23 and 24:
particles. Because of the introduct
Page 25 and 26:
which is introduced for mass genera
Page 27 and 28:
2.3 Top Quark The large mass of the
Page 29 and 30:
ATLAS Preliminary Data 2011 Channel
Page 31 and 32:
as the masses of the quarks involve
Page 33 and 34:
LEP HERA Tevatron LHC BR(t → qγ)
Page 35 and 36:
to Wtb couplings, where limits on a
Page 37 and 38:
tion at the collision point, and F
Page 39 and 40:
The positive x-direction is defined
Page 41 and 42: large air-core toroids (one barrel
Page 43 and 44: 3.3.3 Calorimetry The calorimetry i
Page 45 and 46: of ∼ 1% for the H → γγ and H
Page 47 and 48: esolution of 1 cm×1 ns with digita
Page 49 and 50: Luminosity measurement Accurate det
Page 51 and 52: least one hit on the A-side, at lea
Page 53 and 54: caps. The calorimeter selections ar
Page 55 and 56: ut instead fragment to color neutra
Page 57 and 58: Decays A large fraction of the part
Page 59 and 60: The ALGPEN program with HERWIG show
Page 61 and 62: Normalized to unit / 1.96429 GeV No
Page 63 and 64: Chapter 5 Event Selection 5.1 Intro
Page 65 and 66: Variable Cut pT >20 GeV Type MuID t
Page 67 and 68: Identification efficiency eff id 1
Page 69 and 70: (a) (b) Figure 5.4: Electron identi
Page 71 and 72: ε (P ) µ TL T 1 TL µ ε TL µ ε
Page 73 and 74: Jets in this analysis are reconstru
Page 75 and 76: impact parameter significance of we
Page 77 and 78: event is also discarded. Events wit
Page 79 and 80: event kinematics, however no b-jet
Page 81 and 82: Events / 10 GeV trackleptons / 10
Page 83 and 84: analysis, is 22%. Figure 5.13(a) sh
Page 85 and 86: transverse momentum of the leading
Page 87 and 88: Events / 10 GeV Events / 10 GeV 14
Page 89 and 90: two background sources, diboson and
Page 91: ID leptons provides three different
Page 95 and 96: data, has systematic uncertainties
Page 97 and 98: Jets The jet energy scale (JES) and
Page 99 and 100: the fake prediction was scaled down
Page 101 and 102: two or more, and events with E miss
Page 103 and 104: Source MC Background Luminosity ±
Page 105 and 106: Chapter 8 Limit Evaluation 8.1 Intr
Page 107 and 108: means: Q = L( X,s + b) L( , (8.5)
Page 109 and 110: computed from Equation 8.12 replaci
Page 111 and 112: Chapter 9 Conclusions A search for
Page 113 and 114: There are a total of 666236 γ+jets
Page 115 and 116: Appendix B Backgrounds to the 3ID a
Page 117 and 118: Appendix C Systematic Uncertainties
Page 119 and 120: References [1] J. L. Borges, Tres v
Page 121 and 122: [40] G. Lu, F. Yin, X. Wang and L.
Page 123 and 124: [82] ATLAS Collaboration, Expected
show all

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

Create successful ePaper yourself

Delete template?

Save as template?