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We develop a SU(3)C⊗SU(3)L⊗U(1)X model where the number of fermion generations is fixed by cancellation of gauge anomalies, being a type of 3-3-1 model with new charged leptons. Similarly to the economical 3-3-1 models, symmetry breaking is achieved effectively with two scalar triplets so that the spectrum of scalar particles at the TeV scale contains just two CP even scalars, one of which is the recently discovered Higgs boson, plus a charged scalar. Such a scalar sector is simpler than the one in the Two Higgs Doublet Model, hence more attractive for phenomenological studies, and has no flavor changing neutral currents (FCNC) mediated by scalars except for the ones induced by the mixing of Standard Model (SM) fermions with heavy fermions. We identify a global residual symmetry of the model which guarantees mass degeneracies and some massless fermions whose masses need to be generated by the introduction of effective operators. The fermion masses so generated require less fine-tuning for most of the SM fermions and FCNC are naturally suppressed by the small mixing between the third family of quarks and the rest. The effective setting is justified by an ultraviolet completion of the model from which the effective operators emerge naturally. A detailed particle mass spectrum is presented, and an analysis of the Z′ production at the LHC run II is performed to show that it could be easily detected by considering the invariant mass and transverse momentum distributions in the dimuon channel.

We discuss gauge models incorporating $��-��$ flavored CP symmetry (called CP$^{����}$ in the text) in combination with $L_��-L_��$ invariance to understand neutrino mixings and discuss their phenomenological implications. We show that viable leptogenesis in this setting requires that the lightest right-handed neutrino mass must be between $10^9-10^{12}$ GeV and for effective two hierarchical right-handed neutrinos, leptogenesis takes place only in a narrower range of $5\times 10^{10}-10^{12}$ GeV. A multi-Higgs realization of this idea implies that there must be a pseudoscalar Higgs boson with mass less than 300 GeV. Generically, the vev alignment problem can be naturally avoided in our setting., 34pp. v3: matches journal version

Made available in DSpace on 2016-05-17T16:50:53Z (GMT). No. of bitstreams: 0 Previous issue date: 2007-03-30. Added 1 bitstream(s) on 2016-05-17T16:54:21Z : No. of bitstreams: 1 000855449.pdf: 4043234 bytes, checksum: 764d71e0d48fbcfce543c2becab2c918 (MD5) Esta tese visa ao estudo das propriedades de violação de CP e mistura de sabor no Modelo Padrão (MP) e em extensões do mesmo. Estudaremos a conexão entre os dois fenômenos e a relação com os espaços formados pela replicação de multipletos de gauge, os quais chamaremos de espaços horizontais, presentes nos modelos. A presença de tais espaços em teorias de gauge é condição necessária para o aparecimento de mistura de sabor ao nível lagrangiano. Esta pode introduzir novas fontes de violação de CP, como no mecanismo de violação espontânea de CP (VECP), bem como, às vezes, dificultar a análise das propriedades de CP da teoria devido à liberdade de rotação nesses espaços (transformações horizontais). A relação entre replicação de multipletos escalares e violação de CP é investigada em extensões do MP com N dubletos de Higgs. No potencial escalar desses modelos as condições necessárias e suficientes para a violação explícita e espontânea de CP são estudadas e invariantes ímpares por CP, como invariante de Jarlskog no MP, são encontrados. Nessa mesma classe de modelos, o mecanismo de violação espontânea de CP é ilustrado nos modelos com dois e três dubletos, conjuntamente com as restrições impostas pela necessidade de supressão das correntes neutras que trocam sabor. A violação soft de CP é ilustrada em um modelo baseado no grupo de gauge eletrofraco SU(3)L x U(1)N e mostrado que pode acomodar a fenomenologia de violação de CP no sistema dos káons neutros mesmo quando o mecanismo CKM é desligado e toda a assimetria CP é proveniente da troca de férmions exóticos. O fenômeno de mistura de sabor é investigado no âmbito da oscilação de neutrinos, sob o ponto de vista de campos clássicos relativísticos, que incluem aspectos de localização, a fim de procurar por novos efeitos e desvios... he aim of this thesis is the study of the properties of CP violation and flavor mixing in the Standard Model (SM) and in some of its extensions. We study the connection between both phenomena and their relation with the space formed by the replication of gauge multiplets, which will be called horizontal spaces, present in the models. The presence of such spaces in gauge theories is a necessary condition for the appearance of flavor mixing at the Lagrangian level. These identical multiplets can introduce new sources of CP violation, as in the mechanism of spontaneous CP violation (SCPV), and, sometimes, make difficult the analysis of the CP properties of the theory, due to the freedom to rotate the basis of such spaces. The relation between the replication of scalar multiplets and CP violation is investigated in extensions of the SM with N-Higgs-doublets. In the scalar potential of these models the necessary and sufficient conditions for explicit and spontaneous CP violation are studied and CP odd invariants, like the Jarlskog invariant in the SM, are found. In these class of models, the SCPV mechanism is illustrated in the 2-Higgs- and 3-Higgs-doublet models, and the restrictions imposed by the suppression of flavor changing neutral currents are also exposed. The soft CP violation is illustrated in a model based in the gauge group SU(3)L x U(1)N nd it is shown that it can accommodate the phenomenology of the CP violation of the neutral kaons system even when the CKM mechanism is switched off and all CP violation effects are mediated by exotic fermions. The flavor mixing phenomenon is investigated through neutrino flavor oscillations from the perspective of classical relativistic field theories taking localization aspects intoaccount to search for new effects and observable deviations from the usual oscillation formulas...