Advances in Jet Substructure at the LHC: Algorithms, Measurements and Searches for New Physical Phenomena

Description

This book introduces the reader to the field of jet substructure, starting from the basic considerations for capturing decays of boosted particles in individual jets, to explaining state-of-the-art techniques. Jet substructure methods have become ubiquitous in data analyses at the LHC, with diverse applications stemming from the abundance of jets in proton-proton collisions, the presence of pileup and multiple interactions, and the need to reconstruct and identify decays of highly-Lorentz boosted particles. The last decade has seen a vast increase in our knowledge of all aspects of the field, with a proliferation of new jet substructure algorithms, calculations and measurements which are presented in this book.  Recent developments and algorithms are described and put into the larger experimental context. Their usefulness and application are shown in many demonstrative examples and the phenomenological and experimental effects influencing their performance are discussed. A comprehensive overview is given of measurements and searches for new phenomena performed by the ATLAS and CMS Collaborations. This book shows the impressive versatility of jet substructure methods at the LHC. Preface Contents Acronyms 1 Introduction 2 Phenomenology of Jet Substructure 2.1 Introduction to Jet Substructure 2.2 General Considerations 2.2.1 Heavy Particle Decays 2.2.2 W Boson Decay 2.2.3 Z Boson Decay 2.2.4 Higgs Boson Decay 2.2.5 Top Quark Decay 2.2.6 Kinematic Considerations 2.2.7 Kinematics of Vector and Higgs Boson Decays 2.2.8 Kinematics of Top Quark Decays 2.3 Jet Algorithms 2.3.1 Sequential Clustering Algorithms 2.3.2 Variable R Algorithm 2.3.3 XCone 2.3.4 The Georgi Algorithm 2.4 Identifying Particle Decays with Jet Substructure 2.4.1 Jet Mass 2.4.2 Angularities and Energy Correlations 2.4.3 Jet Grooming and N-Prong Taggers 2.4.4 Other Methods 2.4.5 Pileup Mitigation 2.5 (Semi-)Analytical Calculations 2.5.1 Perturbative Effects 2.5.2 Non-perturbative Effects 2.6 Event Generators 2.6.1 Parton Distribution Functions 2.6.2 Matrix Elements 2.6.3 Parton Showers 2.6.4 Matching Matrix Elements to Parton Showers 2.6.5 Multiple Parton Interactions 2.6.6 Hadronisation 2.6.7 Tuning 3 Jet Substructure at the LHC 3.1 ATLAS and CMS Detectors 3.2 Jet Reconstruction and Calibration 3.3 Pileup Mitigation 3.3.1 Mitigation Methods 3.3.2 Performance Studies 3.4 Grooming Methods 3.5 Jet Substructure Tagging 3.5.1 Quark/Gluon Discrimination 3.5.2 Vector Boson Tagging 3.5.3 Higgs Boson Tagging 3.5.4 Top Tagging 3.5.5 Machine Learning Taggers 4 Standard Model Measurements 4.1 Measurements of Jet Substructure Observables 4.1.1 Jet Mass of Light Flavour and Gluon Jets 4.1.2 Jet Mass of W and Z Jets 4.1.3 Jet Mass of Top Quark Jets 4.1.4 Jet Substructure in Light Flavour and Gluon Jets 4.1.5 Jet Substructure in W and Top Jets 4.2 Measurements Using Jet Substructure 4.2.1 Electroweak Boson Production 4.2.2 Higgs Boson Production 4.2.3 Top Quark Production 5 Direct Searches for New Physics 5.1 Diboson Resonances 5.1.1 WW, WZ and ZZ Resonances 5.1.2 WH and ZH Resonances 5.1.3 HH Resonances 5.1.4 Combinations 5.1.5 V γ and H γ Resonances 5.2 Resonances Coupling to Third Generation Quarks 5.2.1 toverlinet Resonances 5.2.2 toverlineb Resonances 5.3 Vector-Like Quarks 5.3.1 Pair Production 5.3.2 Single Production 5.3.3 Production Through Resonance Decays 5.4 Excited Third Generation Quarks 5.5 Dark Matter and Mono-X 5.6 Light Resonances Coupling to Quarks or Gluons 5.7 Supersymmetry 5.8 Leptoquarks 6 Summary Appendix References Index