Study of the yukawa coupling to leptons using pp collisions at √s = 13 tev with the atlas detector
- Autores: Sergi Rodriguez Bosca
- Directores de la Tesis: Luca Fiorini (dir. tes.)
- Lectura: En la Universitat de València ( España ) en 2020
- Idioma: español
- Tribunal Calificador de la Tesis: María Victoria Castillo Jiménez (presid.), Tomas Davidek (secret.), Simonetta Gentile (voc.)
- Programa de doctorado: Programa de Doctorado en Física por la Universitat de València (Estudi General)
- Materias:
- Enlaces
- Tesis en acceso abierto en: RODERIC
- Resumen
The work reported in this thesis was carried out during the Run 2 operation years of the Large Hadron Collider. It describes two physics analyses where the Yukawa couplings of the Higgs boson have an important role for the understanding of the Higgs boson particle, discovered in July 2012.
The motivation to study the Yukawa couplings lies in the Standard Model of particle physics, which is the best theoretical framework developed so far to describe the behaviour of sub-atomic particles and their interactions. However it has still unsolved problems. For instance the modification of the theory to account for massive neutrinos or why the charged lepton mixing is highly suppressed. Therefore a good understanding and precise measurements of the Standard Model predictions are necessary, in particular in the Yukawa sector of the theory.
At the Large Hadron Collider one possible way to measure the lepton Yukawa coupling of the Higgs boson is through its decay into a pair of tau leptons. The procedure to obtain the cross-section measurement of the Higgs boson is explained in Chapter 4. Additionally, the cross-section is measured independently for the two main production modes of the Higgs boson, gluon-gluon fusion and vector boson fusion.
Several physics results have demonstrated the existence of neutrino oscillations which can only happen if neutrinos are massive. Many non-SM theories assume that the charged lepton mixing could appear in nature allowing lepton flavour violating decays. Two independent searches for decays of the Higgs boson into leptons of different flavours are performed in Chapter 5.
The first part of the thesis sets up the context, both theoretical and experimental, in which the work of this thesis was done. The description of the theoretical framework of the Standard Model, including the Higgs mechanism and the Yukawa interactions is presented in Chapter 1. Chapter 2 describes the experimental setup, the CERN organization, the LHC, the ATLAS experiment and the object reconstruction used in the analyses. Additionally, the Monte Carlo simulations and data-driven techniques used to describe the signal and background processes are described in Chapters 3 and A.1.
Finally, Chapter 6 summarizes the main findings of the thesis and compares them with previous results as well as predictions of the Standard Model of particle physics.
