Quantum effects on some low and high energy processes beyond the standard model
Elementary particle physics has made remarkable progress in the past two decades, both experimentally and theoretically. The success of the Standard Model (SM) has been overwhelming since it was proposed as the unified Theory describing particle physics phenomenology. The only lacking building block...
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| Tipo de recurso: | tesis doctoral |
| Fecha de publicación: | 2002 |
| País: | España |
| Institución: | Universitat Autònoma de Barcelona |
| Repositorio: | Dipòsit Digital de Documents de la UAB |
| Idioma: | inglés |
| OAI Identifier: | oai:ddd.uab.cat:36888 |
| Acceso en línea: | https://ddd.uab.cat/record/36888 |
| Access Level: | acceso abierto |
| Palabra clave: | Model estàndard (Física nuclear) Supersimetria Higgs, Bosons de |
| Sumario: | Elementary particle physics has made remarkable progress in the past two decades, both experimentally and theoretically. The success of the Standard Model (SM) has been overwhelming since it was proposed as the unified Theory describing particle physics phenomenology. The only lacking building block of the SM is the Higgs boson. This is why our interest will be focused in the spontaneous symmetry breaking sector of the theory. From a theoretical point of view, the SM cannot be considered as the ultimate theory because many questions remain open. The SM also lacks a quantum theory of gravity, and the recent indications for the possibility of neutrino oscillations give support to the idea of the SM being subsumed within a more fundamental theory. In this thesis, we study the Higgs boson decaying into quarks. We first depict clearly the low-energy physics constraints from the radiative -decays, within the Minimal Supersymmetric SM (MSSM), and then we study the decay of the charged Higgs into t . We also argue on the important effects that appear in the charged Higgs boson production itself and in the expected measurement of the single top quark production cross-section and their relevance for the Tevatron II analyses. The important supersymmetric strong corrections to the three MSSM neutral Higgs bosons decays are also discussed. As early as in 1995 we suggested that these effects could be important in the Higgs boson production mechanisms themselves and nowadays this has been shown in some partial studies for the Tevatron. We again use the low energy B-meson decay physics experiments constraints. Within the theoretical framework of two-Higgs-doublet models, we study the charged Higgs boson decay of a top quark and a comparison with the SUSY case is done. It gives us knowledge to let us distinguish between the two Higgs sectors. We also improve the existing standard QCD corrected bounds in the parameter space tanb-mH+, obtained by the Tevatron Collaboration, by adding the electroweak effects just calculated. Lastly, a review analysis of the constraints on the masses and couplings of the single and double charge members of Left-Right Higgs triplets is carried out. Present day experiments tolerate values of the Yukawa couplings of these scalars at the level of the standard electroweak gauge couplings. Thus, it is not strange to find that the proposed measurement of the ratio by the Large Cerenkov Detector Project Collaboration would allow exploring a large region of the parameter space inaccessible to the usual ratio measured by the CHARM II Collaboration. |
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