Phenomenological studies of scalar type leptoquarks motivated by Grand Unification models

• Autor(a) principal: Santiago, Eduardo Augusto
• Data de Publicação: 2021
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10773/33871
• topic: Standard model; Beyond the standard model; Anomalies; (g - 2)μ; Rᴅ⁽*⁾; Rĸ⁽*⁾; Leptoquarks

Despite the major success of the Standard Model (SM), it is undeniable that this is not the ultimate theory of particle physics. A number of unexplained phenomena such as neutrino masses, dark matter, dark energy, matter-antimatter asymmetry and a difficulty in accommodating gravity is pleading for Beyond the Standard Model (BSM) physics. In recent years, anomalies such as the measurement of g - 2 of the muon, as well as flavour anomalies presented in the form of Rᴅ⁽*⁾ and Rĸ⁽*⁾ processes have increased in significance, further suggesting the need for BSM physics. In this thesis a model containing four scalar leptoquarks (LQ), particles definitely beyond the SM, aims at explaining just that. This model is inspired by a recently proposed Full Unification E₈ theory where scalar LQs are naturally emergent. By making use of several computational tools including machine learning (ML) based methods, this work intends to explain why such particles, given that they exist, should explain such anomalies. First a theoretical discussion is made in order to get acquainted with its intricacies. Next, via simulations, a phenomenological study is made, from which it is assessed that it indeed explains the g - 2 of the muon, as well as Rᴅ⁽*⁾ . Unfortunately it is unable to explain Rĸ⁽*⁾, however, a potential solution that is feasible in the context of the E₈ model, on which this work is based, is briefly addressed.