PROBING BEYOND the STANDARD MODEL PHYSICS USING EFFECTIVE FIELD THEORY a Dissertation Aimed at the Achievement of Ph.D

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The access to the contents of this doctoral thesis it is limited to the acceptance of the use conditions set by the following Creative Commons license: https://creativecommons.org/licenses/?lang=en PROBING BEYOND THE STANDARD MODEL PHYSICS USING EFFECTIVE FIELD THEORY A dissertation aimed at the achievement of Ph.D. in physics Author THIBAUD VANTALON Supervisor Tutor Prof. Christophe Grojean Dr. Oriol Pujolás Boix Institut de Física d’Altes Energies Grup de Física Teòrica Departament de Física – Facultat de Ciències Universitat Autònoma de Barcelona 2018 Probing beyond the Standard Model physics using effective field theory A dissertation aimed at the achievement of Ph.D. in physics Author: Thibaud Vantalon Supervisor: Tutor: Prof. Christophe Grojean Dr. Oriol Pujolás Boix Institut de Física d’Altes Energies Grup de Física Teòrica Departament de Física – Facultat de Ciències Universitat Autònoma de Barcelona February 26, 2018 To the tuning which brought me here. Research is a wasteful process — Gian Francesco Giudice ABSTRACT Now the LHC has provided 120 fb−1 of data, the evidence for an energy gap between the Standard Model (SM) and new physics has grown strong. This makes effective field theory (EFT) a versatile method to constrain new physics with minimal model dependence. In this thesis, based on work done during my PhD candidature [1–4], we make use of EFT techniques in a variety of studies. We start by exploring the prospect of extracting the Higgs trilinear self-coupling at current hadron and future lepton colliders, using both higher order corrections to the single-Higgs process and di-Higgs production. Our analysis minimizes model dependence thanks to the use of EFT. We argue that in order to constrain the different possible deviations to the Standard Model, a global fit with the inclusion of as many observables as possible is needed. We found that the inclusion of the trilinear correction in single-Higgs processes has a marginal effect at the LHC and will give a bound on the trilinear of order one. The situation is different at lepton colliders, where the high precision and different running energies can give bound of order 50%. We then extend our EFT by adding a scalar singlet to study the CP properties of the particle which could have been behind the infamous 750 GeV di-photon excess. We define the CP sensitive asymmetries, in both the vector and gluon fusion channels, and study their power to differentiate between the CP odd or even hypotheses. Finally, we move somewhat away from EFT, and use a simplified model to compare the constraints on composite Higgs models coming from low energy neutron and electron electric dipole moment (EDM) measurements and LHC searches. Effective field theory is not completely absent, since we compute the two loop corrections of the light quarks and leptons EDM to match our simplified model to the higher dimensional operators of a low energy effective Lagrangian, and obtain bounds for our model. We then recast LHC searches and compare the present and future bounds. We found that the current bounds are competitive with the one coming from the LHC direct search and are of order a few TeV. The future upgrade of the experiment measuring the electron dipole moment should bring the bounds to the 5-10 TeV range. LISTOFWORKS Papers realized during the PhD and presented in this thesis: 1.Probing light top partners with CP violation Giuliano Panico, Marc Riembau , Thibaud Vantalon Submitted to JHEP for publication, arXiv:1712.06337 [hep-ph] 2.A global view on the Higgs self-coupling at lepton colliders Stefano Di Vita, Gauthier Durieux, Christophe Grojean, Jiayin Gu, Zhen Liu, Giu- liano Panico, Marc Riembau, Thibaud Vantalon JHEP to be published, arXiv:1711.03978 [hep-ph] 3.A global view on the Higgs self-coupling Stefano Di Vita, Christophe Grojean, Giuliano Panico, Marc Riembau, Thibaud Van- talon. JHEP09(2017)069, arXiv:1704.01953 [hep-ph] 4.Deciphering the CP nature of the 750 GeV resonance Mikael Chala, Christophe Grojean, Marc Riembau, Thibaud Vantalon Phys. lett. B. 2016.06.050, arXiv:1604.02029 [hep-ph] Paper realized before the PhD: 5.Composite Charge 8/3 Resonances at the LHC Oleksii Matsedonskyi, Francesco Riva, Thibaud Vantalon JHEP1404(2014)059, arXiv:1401.3740 [hep-ph] ACKNOWLEDGEMENT I am monstrously grateful to all the people without whom I would not be here today. In a somehow chronological order, Je veux commencer par remercier toute ma famille et particulièrement, ma mère Mar- tine, mon père, Jacky et ma grande petite sœur Sarah qui ont toujours été là pour moi. Un énorme merci à tous mes amis d’enfance en commençant par Louis à qui je dois la plupart de mon savoir informatique. Mes amis Corentin, Jérôme, Cyril, Antony, Arnaud sur qui je pourrai toujours compter. L’ordre chronologique nous amène finalement où les choses sérieuses ont commencé. Je voudrai remercier les “3 Mousquetaires”, Sam, Emmanuel et Victor sans qui tout aurai été “vachement” moins drôle ! Which bring us to Riccardo Rattazzi and Francesco Riva, who introduced me to quan- tum field theory and helped me to get my PhD student position. Which at last bring me to Christophe Grojean who accepted me as his student and taught me and helped me during those four years. A big thank to José Ramón Espinosa Sedano for the physics discussion. Without him, Clara and the two Marc my Catalan and Spanish level would never have allowed me to survived the Spanish administration. I am also very grateful to my IFAE and DESY colleagues and friends, (Marc)i1, Clara, Mateo, Mat2eo (no higher order presently known), Sergi, Joan, Lindber, Xabier, Bernat, Daniel, Oriol, Sebastian, Oleksii, Marco, Felix, Filippo, Iason, Jiayin, Nayara, Yann, Thomas, Valerie, Yannick, Riccardo, Benedict, Ibrahim. A special mention is worth for my collabo- rators Giuliano, Marc, Stefano, Jiayin, Zhen, Gauthier, Mikael, Emanuele and Christophe. A special thanks to the bouldering crew especially Rob Klabbers for the extra challenge! And my flatmate for the Catan game and the fun time: Moli, Alex, Javier, Anna, Christoph, Frederike, Jakab. A huge thanks to Jérome for the title page and Iason, Gauthier, Benedict and Nayara for their valuable comments and try to minimize the number of spelling mistakes. I am also grateful to the creators of the classicthesis LATEX template which I used to write this document. 1 With i the generation index running from 1 to 2 CONTENTS Abstract vii List of works ix Acknowledgement xi Preface 1 Disclaimer 3 i the framework 1 the standard model 7 1.1 Fields and symmetries 7 1.2 The Brout-Englert-Higgs mechanism 9 1.2.1 Gauge boson masses 9 1.2.2 Fermion masses and implications 12 1.3 The θ¯ parameters 13 1.4 The Standard Model in numbers 14 1.5 New physics opportunities 16 2 effective field theory 19 2.1 The SM as an EFT 19 2.2 The standard model EFT 19 ii constraining the standard model eft 3 which higgs? 29 3.1 Current constraints 29 3.2 Parameterizing new physics in the Higgs sector 32 3.2.1 Higgs primary couplings 32 3.2.2 Additional operators contributing to Higgs observables 35 3.2.3 Large Higgs self-interactions in a consistent EFT expansion 37 4 testing the higgs trilinear at a hadron collider 41 4.1 Fit from inclusive single-Higgs measurements 41 4.1.1 Single-Higgs rates and single-Higgs couplings 42 4.1.2 Global fit including Higgs self-coupling 47 4.1.3 Impact of the trilinear coupling on single-Higgs couplings 49 4.2 Double-Higgs production 50 4.3 Differential observables 53 4.3.1 Impact of single-Higgs differential measurements 53 4.3.2 Robustness of the fits 55 4.4 The trilinear at HL-LHC 57 5 testing the higgs trilinear at lepton colliders 61 5.1 Future machines 61 5.2 Low-energy lepton machines 62 5.2.1 Higher-order corrections to single-Higgs processes 63 5.2.2 Global analysis 65 5.3 High-energy lepton machines 71 5.3.1 Higgs pair production 71 xiv contents 5.3.2 Global analysis 75 5.4 The trilinear at lepton colliders 78 6 present and future of the trilinear 81 iii testing new physics using eft 7 parity of a scalar particle decaying into photons 85 7.1 Context 85 7.2 Parameterization and constraints 86 7.3 Different channels 88 7.3.1 Associated production 88 7.3.2 Gluon fusion 91 7.3.3 Vector-boson fusion 94 7.4 Results 97 7.5 Conclusions 98 8 probing light top partners with cp violation 101 8.1 Introduction 101 8.2 Effects of composite Higgs models 101 8.3 CP violation from top partners 104 8.3.1 Electron EDM 106 8.3.2 CP-violating effects for the light quarks 111 8.3.3 Experimental bounds 115 8.3.4 Comparison with direct top partner searches 118 8.4 Non-minimal models 120 8.4.1 The 14 + 1 model with a light singlet 121 8.4.2 The 5 + 5 2-site model 123 8.5 Conclusions 127 9 closing words 129 iv appendix a the trilinear at hadron colliders 133 a.1 Parametrizing EFT cross sections using MadGraph 133 a.2 Higgs production and decay rates in the EFT framework 134 b the trilinear at lepton colliders 141 b.1 One-loop corrections from δκλ 141 b.2 Additional results 141 c statistical refinement on asymmetry 147 d top partners production cross section 149 Glossary 151 bibliography 155 PREFACE July 4, 2012, early morning, after an overnight wait for some, people are impatiently in line, not for the new trendy gadget or to watch the premier of the new blockbuster movie, this queue is not in front of a shop, or a cinema but in front of an auditorium at conseil européen pour la recherche nucléaire (CERN).

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