Tesis doctoral de Paula Tuzón Marco
Despite the successful description of the observed phenomena given by the sm, it leaves many questions unanswered, a big part of them related with the flavour structure itself. The gauge and scalar sectors have 4 free parameters, alpha_{em}, m_z, g_f, which are very well determined, and the mass of the higgs, m_h. Anyway, a model with only 4 degrees of freedom permits to make rather good predictions. However, the fermionic flavour sector introduces 13 more, with 9 fermion masses, 3 mixings and 1 phase. And moreover, if one takes into account that neutrinos are actually massive, 3 more masses need to be added, plus the corresponding mixing matrix for the lepton sector (other 4 parameters, plus 2 new phases if neutrinos are majorana particles). The existence of all these degrees of freedom comes from the unknown yukawa couplings, the origin and the structure of which conform an unresolved flavour puzzle. The scalar sector plays an important role in its structure, since the generation of masses is completely related with the electroweak ssb, the most obscure part of the sm lagrangian. A cp violation mechanism is incorporated by the sm through a single phase in the v matrix. Although it explains (by now) all the observed cp violating phenomena in the laboratory, this mechanism is not enough to describe the matter-antimatter asymmetry of the universe. Therefore, a fundamental explanation of the origin of cp violation is still absent. Neutrino oscillations are the first phenomenon towards the existence of new flavour physics; in this sense, lepton flavour violation opens a window to a new flavour dynamics lacking in the sm. apart from the gim mechanism there is nothing constraining the structure of the flavour sector, giving a lot of space for new physics proposals. A simple and versatile modification (appropriate enlargement) of the scalar sector origins many new dynamical possibilities while respecting the sm constraints. In this thesis we aim to perform an analysis of the electroweak model with a non-minimal scalar sector, in particular, we study different aspects of the two-higgs-doublet model. we first present some features about the general 2hdm, in particular, we perform a general discussion about lepton flavour violation (lfv), which is allowed in this case. In the two next chapters, we discuss further the general structure of this new aligned 2hdm (a2hdm) together with some relevant phenomenological implications. And finally, in the last chapter, we study also the 2hdm in the presence of an extra u(1) gauge boson, generating a framework similar to the inert model.
Datos académicos de la tesis doctoral «Tests of the electroweak model in the presence of two higgs doublets«
- Título de la tesis: Tests of the electroweak model in the presence of two higgs doublets
- Autor: Paula Tuzón Marco
- Universidad: Universitat de valéncia (estudi general)
- Fecha de lectura de la tesis: 12/09/2011
Dirección y tribunal
- Director de la tesis
- Antonio Pich Zardoya
- Tribunal
- Presidente del tribunal: Francisco jose Botella olcina
- siannah Peñaranda rivas (vocal)
- María margarida Nesbitt rebelo (vocal)
- alejandro Ibarra sixto (vocal)