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

More documents

Recommendations

Info

Contents vi Electron reconstruction in the calorimeter . . . . . . . . . . . 120 Photon reconstruction in the calorimeter . . . . . . . . . . . . 121 Reconstruction of missing transverse energy . . . . . . . . . . 122 4.2.3 Reconstruction in the Muon Spectrometer . . . . . . . . . . . 124 Standalone muon reconstruction . . . . . . . . . . . . . . . . . 125 Combined muon reconstruction . . . . . . . . . . . . . . . . . 134 Inner detector based muon tagging . . . . . . . . . . . . . . . 136 Calorimeter-based muon tagging . . . . . . . . . . . . . . . . . 137 4.2.4 Efficiencies in the muon system . . . . . . . . . . . . . . . . . 138 Drift tube efficiency . . . . . . . . . . . . . . . . . . . . . . . . 139 Reconstruction efficiency of combined muon tracks . . . . . . 143 5 Monte Carlo Simulation 152 5.1 Overview of Monte Carlo event generation and simulation . . . . . . 152 5.2 Monte Carlo generators used in this analysis . . . . . . . . . . . . . . 154 5.2.1 Pythia . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 154 5.2.2 POWHEG . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 155 5.2.3 FEWZ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 156 5.2.4 Monte Carlo samples used in this analysis . . . . . . . . . . . 157 5.2.5 The ATLAS detector simulation . . . . . . . . . . . . . . . . . 157 6 Event Selection 160 6.1 Z event selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160 6.1.1 Properties of the preselected sample . . . . . . . . . . . . . . . 165 Hit distributions . . . . . . . . . . . . . . . . . . . . . . . . . 165 Kinematic distributions . . . . . . . . . . . . . . . . . . . . . . 171 6.2 Z signal acceptance and efficiencies . . . . . . . . . . . . . . . . . . . 171 6.2.1 Monte Carlo event reweighting owing to pile-up . . . . . . . . 174 6.2.2 Acceptance of Z selection from Monte Carlo cutflow . . . . . . 175 6.2.3 Factorizing the acceptance: AZ and CZ ............. 177 Fiducial acceptance AZ ...................... 177 Event detection efficiency CZ .................. 178 6.2.4 Estimation of efficiency scale factors . . . . . . . . . . . . . . 180 Trigger efficiency for single muons . . . . . . . . . . . . . . . . 180 Trigger efficiency and scale factor for Z → µµ events . . . . . 185 Reconstruction efficiency and scale factor for Z → µµ events . 188 6.2.5 Muon momentum scale and resolution . . . . . . . . . . . . . 189 Muon momentum scale and resolution from cosmic events . . 192 Effect of momentum scale and resolution on Z → µµ acceptance 199 6.2.6 Isolation cut efficiency for Z → µµ events . . . . . . . . . . . . 200 6.2.7 Theoretical uncertainty on CZ .................. 202 6.2.8 Summary of systematic uncertainties . . . . . . . . . . . . . . 202
Contents vii 6.2.9 Summary of acceptance and efficiency . . . . . . . . . . . . . . 203 6.2.10 Decomposition of CZ ....................... 204 7 Background Estimation 207 7.1 QCD background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 208 7.1.1 Data-driven QCD background estimation . . . . . . . . . . . . 208 Exponential fit to the Mµµ distribution . . . . . . . . . . . . . 208 Template fitting with 3.37 pb −1 ................. 209 7.2 Electroweak backgrounds . . . . . . . . . . . . . . . . . . . . . . . . . 217 7.2.1 t¯t background . . . . . . . . . . . . . . . . . . . . . . . . . . . 217 7.2.2 Z → ττ background . . . . . . . . . . . . . . . . . . . . . . . 218 7.2.3 W → µν backgrounds . . . . . . . . . . . . . . . . . . . . . . 218 7.3 Cosmic ray background . . . . . . . . . . . . . . . . . . . . . . . . . . 219 7.4 Summary of backgrounds . . . . . . . . . . . . . . . . . . . . . . . . . 222 8 Properties of Z bosons and measurement of Z → µµ cross-section 223 8.1 Z candidate events . . . . . . . . . . . . . . . . . . . . . . . . . . . . 223 8.1.1 Properties of Z → µµ events . . . . . . . . . . . . . . . . . . . 224 Hit distributions . . . . . . . . . . . . . . . . . . . . . . . . . 225 Kinematic distributions . . . . . . . . . . . . . . . . . . . . . . 227 8.1.2 Fitting the Z peak and extraction of Z mass resolution . . . . 228 8.2 Cross-section measurement . . . . . . . . . . . . . . . . . . . . . . . . 234 9 Discussion and Outlook 235 9.1 Comparison with theoretical prediction . . . . . . . . . . . . . . . . . 235 9.2 Outlook . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 238 A Event list 244 B Comparison of muon curvature in cosmic events 248 Bibliography 250
Page 1: Measurement of the Z boson cross-se
Page 4 and 5: Contents Title Page . . . . . . . .
Page 8 and 9: List of Figures 1.1 Proton structur
Page 10 and 11: List of Figures x 6.17 Muon pT scal
Page 12 and 13: List of Tables xii 6.18 Decompositi
Page 14 and 15: Acknowledgments xiv mate Niels van
Page 16 and 17: Chapter 1: Introduction and Theoret
Page 24: Chapter 1: Introduction and Theoret
Page 48 and 49: Chapter 2 The Accelerator and the E
Page 50: Chapter 2: The Accelerator and the
Page 53 and 54: Chapter 2: The Accelerator and the
Page 55 and 56: Chapter 2: The Accelerator and the
Page 57:
Chapter 2: The Accelerator and the
Page 60 and 61:
Page 63:
Page 66 and 67:
Page 68 and 69:
Page 70 and 71:
Page 72 and 73:
Page 74 and 75:
Page 76 and 77:
Page 78 and 79:
Page 80:
Chapter 3 Luminosity Measurement at
Page 87 and 88:
Chapter 3: Luminosity Measurement a
Page 89 and 90:
Page 91 and 92:
Page 93 and 94:
Page 95 and 96:
Page 97 and 98:
Page 99 and 100:
Page 101 and 102:
Page 103 and 104:
Page 105 and 106:
Page 107 and 108:
Page 109 and 110:
Chapter 4: Data Collection and Even
Page 111 and 112:
Page 113 and 114:
Page 115 and 116:
Page 117 and 118:
Page 119 and 120:
Page 121 and 122:
Page 123 and 124:
Page 125 and 126:
Page 127 and 128:
Page 129 and 130:
Page 131 and 132:
Page 133 and 134:
Page 135:
Page 140:
Page 143 and 144:
Page 145 and 146:
Page 147 and 148:
Page 149 and 150:
Page 151 and 152:
Page 153 and 154:
Page 155 and 156:
Page 157:
Page 160 and 161:
Page 162:
Page 165 and 166:
Page 167 and 168:
Chapter 5: Monte Carlo Simulation 1
Page 169 and 170:
Page 171:
Page 174 and 175:
Chapter 6 Event Selection After eve
Page 177 and 178:
Chapter 6: Event Selection 163 - In
Page 179 and 180:
Chapter 6: Event Selection 165 Figu
Page 181 and 182:
Chapter 6: Event Selection 167 with
Page 183 and 184:
Chapter 6: Event Selection 169 Entr
Page 185 and 186:
Chapter 6: Event Selection 171 Entr
Page 187 and 188:
Chapter 6: Event Selection 173 T p
Page 189 and 190:
Page 191:
Chapter 6: Event Selection 177 6.2.
Page 197 and 198:
Page 199:
Chapter 6: Event Selection 185 are
Page 203 and 204:
Chapter 6: Event Selection 189 Reco
Page 205 and 206:
Chapter 6: Event Selection 191 smea
Page 207 and 208:
Chapter 6: Event Selection 193 Firs
Page 211 and 212:
Chapter 6: Event Selection 197 Para
Page 213 and 214:
Chapter 6: Event Selection 199 the
Page 217:
Chapter 6: Event Selection 203 Para
Page 222 and 223:
Chapter 7: Background Estimation 20
Page 224 and 225:
Page 226 and 227:
Page 228 and 229:
Page 230 and 231:
Page 232 and 233:
Page 234 and 235:
Page 236 and 237:
Page 238 and 239:
Chapter 8: Properties of Z bosons a
Page 240 and 241:
Page 242 and 243:
Page 244 and 245:
Page 246 and 247:
Page 248:
Page 253 and 254:
Chapter 9: Discussion and Outlook 2
Page 255 and 256:
Page 257 and 258:
Page 259 and 260:
Appendix A: Event list 245 Candidat
Page 261 and 262:
Appendix A: Event list 247 Candidat
Page 263 and 264:
Appendix B: Comparison of muon curv
Page 265 and 266:
Bibliography 251 [13] S. Ask. Statu
Page 267 and 268:
Bibliography 253 [44] S. Frixione,
Page 269 and 270:
Bibliography 255 [75] N. E. Adam an
Page 271:
Bibliography 257 [102] The TOTEM Co
show all

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

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?