Measurements of observables sensitive to colour reconnection in tt events with the ATLAS detector at s = 13 TeV / vorgelegt von Shayma Wahdan. Wuppertal, October 2022
Content
1 Introduction
2 The Standard Model and the top quark
3 Event generation and simulation
4 The LHC and the ATLAS experiment
5 Physics objects and observables definition
5.1 Detector-level objects definition
5.2 Particle-level objects definition
5.3 Event selection
5.4 Observables definition
5.5 Analysis strategy
6 Backgrounds estimation and corrections to observables
6.1 Event-based backgrounds estimation
6.2 Track-based backgrounds estimation
6.2.1 Estimation of the number of secondary and pile-up tracks
6.2.2 Estimation of the secondaries and pile-up scale factors
6.2.3 Systematic uncertainties in the pile-up scale factor estimation
6.2.4 Estimation of track-backgrounds contamination to the ∑ntrk,outpT observable
6.3 Corrections to observables
7 Differential cross-section measurement
7.1 Formulation of the unfolding problem
7.2 The Iterative Bayesian unfolding method
7.3 Extraction of differential cross-sections
7.4 Binning optimisation
7.5 Unfolding validation tests
8 Systematic uncertainties
8.1 Experimental uncertainties
8.2 Signal modelling uncertainties
8.3 Background modelling uncertainties
8.4 Unfolding-technique uncertainties
8.5 Statistical uncertainty
8.6 Total uncertainty
9 Results and interpretation
9.1 Particle-level normalised differential cross-section results
9.2 Interpretation: χ2 evaluation
9.3 Total fiducial cross-section
10 Summary and conclusions
A Simulated samples
B Systematic uncertainties
C Particle-level absolute differential cross-section results
Bibliography
List of Figures
List of Tables
Acknowledgements