| Author |
Berlingen, Javier Montejo,
|
| Series |
Springer theses |
|
Springer theses.
|
| Subject |
Quantum flavor dynamics.
|
|
Quarks.
|
| Description |
1 online resource (xiv, 283 pages) : illustrations (some color). |
|
polychrome rdacc |
| Note |
"Doctoral thesis accepted by the Autonomous University of Barcelona, Spain." |
| Bibliography Note |
Includes bibliographical references. |
| Contents |
Supervisor's Foreword; Publications related to this thesis:; Contents; Preamble; 1 Introduction and Theoretical Framework; 1.1 The Standard Model; 1.1.1 Electroweak Theory; 1.1.2 The Higgs -- Englert -- Brout Mechanism; 1.1.3 Quantum Chromodynamics; 1.1.4 Experimental Successes of the Standard Model; 1.1.5 Shortcomings of the Standard Model; 1.2 Beyond the Standard Model; 1.2.1 Supersymmetry; 1.2.2 Extra Dimensions; 1.2.3 Compositeness; 1.3 Signatures of BSM Theories; 1.3.1 Fermionic Top Partners: Vector-Like Quarks; 1.3.2 Bosonic Top Partners: Stops; 1.3.3 Four-top-quark Production; References. |
|
2 The ATLAS Experiment at the Large Hadron Collider2.1 The Large Hadron Collider; 2.2 The ATLAS Experiment; 2.2.1 Coordinate System; 2.2.2 Magnet System; 2.2.3 Inner Detector; 2.2.4 Calorimeters; 2.2.5 Muon Spectrometers; 2.3 Forward Subdetectors and Luminosity Measurement; 2.4 Trigger System; 2.5 Data Quality; References; 3 Event Simulation; 3.1 Simulation of pp Collisions; 3.1.1 Factorization Theorem; 3.1.2 Fixed Order QCD: Matrix Elements; 3.1.3 Parton Shower; 3.1.4 Matrix Element and Parton Shower Matching; 3.1.5 Hadronization; 3.1.6 Underlying Event; 3.1.7 Pile-up. |
|
3.2 Monte Carlo Generators3.2.1 General Purpose Monte Carlo Generators; 3.2.2 Multi-leg Leading-Order Generators; 3.2.3 NLO Generators; 3.3 ATLAS Simulation; 3.4 Monte Carlo Corrections; References; 4 Reconstruction of Physics Objects; 4.1 Tracks; 4.2 Primary Vertices; 4.3 Leptons; 4.3.1 Electrons; 4.3.2 Muons; 4.4 Jets; 4.4.1 Cluster Formation; 4.4.2 Jet-Finding Algorithm; 4.4.3 Jet Calibration; 4.4.4 Jet Energy Scale Uncertainty; 4.4.5 Jet Energy Resolution; 4.4.6 Jet Reconstruction Efficiency; 4.4.7 Jet Cleaning and Jet Vertex Fraction; 4.5 b-tagging; 4.5.1 b-tagging Algorithms. |
|
4.5.2 b-tagging Calibration4.6 Missing Transverse Energy; References; 5 Common Aspects in Searches for New Physics in tbart Final States with Additional Heavy-Flavor Jets; 5.1 Analysis Strategy; 5.2 Data Sample; 5.3 Event Preselection; 5.4 Signal and Background Modeling; 5.4.1 tbart+jets Background; 5.4.2 W/Z+jets Background; 5.4.3 Other Simulated Backgrounds; 5.4.4 Multijet Background; 5.4.5 Signal Modeling; 5.5 Comparison Between Data and Prediction; 5.6 Tag Rate Function Method; 5.7 Systematic Uncertainties; 5.7.1 Luminosity; 5.7.2 Object Definitions; 5.7.3 tbart Modeling Uncertainties. |
|
5.7.4 W/Z+jets Background5.7.5 Other Simulated Backgrounds; 5.7.6 Multijet Background; 5.7.7 Signal Modeling; References; 6 Statistical Analysis; 6.1 Hypothesis Testing; 6.1.1 CLs Method; 6.2 Likelihood Function and Profile Likelihood Ratio; 6.2.1 p-values; 6.2.2 Approximate Distributions for the Test Statistic; 6.2.3 Profiling in Action; References; 7 Searches for New Physics in tbart Final States with Additional Heavy-Flavor Jets; 7.1 Search for tbartH Production; 7.1.1 Event Selection and Categorization; 7.1.2 Discriminant Variable: Artificial Neural Networks; 7.1.3 Neural Network Training. |
| Summary |
This PhD thesis focuses on the search for new phenomena in top-antitop quark (tt) final states with additional b-quark jets at the LHC. It uses the full Run 1 dataset collected by the ATLAS experiment in proton-proton collisions at √s=8 TeV. The final state of interest consists of an isolated lepton, a neutrino and at least six jets with at least four b-tagged jets, a challenging experimental signature owing to the large background from tt+heavy-flavor production. This final state is characteristic of ttH production, with the Higgs boson decaying into bb, a process that allows direct probing of the top-Higgs Yukawa coupling. This signature is also present in many extensions of the Standard Model that have been proposed as solutions to the hierarchy problem, such as supersymmetry or composite Higgs models, which predict the pair production of bosonic or fermionic top quark partners, or the anomalous production of four-top-quark events. All these physics processes have been searched for using an ambitious search strategy that has been developed on the basis of a combination of state-of-art theoretical predictions and a sophisticated statistical analysis to constrain in-situ the large background uncertainties. As a result, the most restrictive bounds to date on the above physics processes have been obtained. |
| Access |
License restrictions may limit access. |
| Note |
Online resource; title from PDF title page (SpringerLink, viewed July 26, 2016). |
| ISBN |
9783319410517 (electronic bk.) |
|
3319410512 (electronic bk.) |
|
3319410504 (print) |
|
9783319410500 (print) |
|
9783319410500 (print) |
| ISBN/ISSN |
10.1007/978-3-319-41051-7 |
| OCLC # |
953969158 |
| Additional Format |
Printed edition: 9783319410500 |
|
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