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Orientador: Vicente Pleitez / Banca: Alex Gomes Dias / Banca: William Antonio Ponce Gutierrez / Banca: Alberto Gago Medina / Banca: Hiroshi Nunokawa / Resumo: Neste trabalho, propomos duas extensões multi-Higgs do modelo padrão com simetrias discretas abelianas e não abelianas e com o setor escalar que possui pelo menos um dubleto de Higgs para cada férmion do MP. Mostramos que do ponto de vista fenomenológico os modelos concordão com os dados experimentais e as massas e as matrizes de mistura CKM e PMNS são corretamente obtidas, para o primeiro modelo que descreve o setor dos quarks e dos léptons e para o segundo modelo, que descreve somente o setor dos léptons a matriz de mistura PMNS e as massas são devidamente obtidas / Abstract: In this work we propose two multi-Higgs extension of the Standard Model with Abelian and non Abelian discrete symmetries and a scalar sector which has at least one Higgs doublet for each fermion of the Standard Model. From the phenomenological point of view the models are safe and the masses and the mixing matrices CKM and PMNS are properly obtained for the first model that describes the sector of quarks and leptons. The second model describes only the leptonic sector, but the mixing matrix and masses are also obtained in compliance with the experimental data / Doutor

Thesis (Ph. D.)--University of Chicago, Dept. of Physics, December 2003. / Includes bibliographical references. Also available on the Internet.

Orientador: Vicente Pleitez. / Doutor

The Interacting Boson Model (IBM) of Arima and Iachello and co-workers is one of the most successful theories for describing the properties of the low-lying energy levels of medium-to-heavy mass nuclei. A review of the principles and phenomenology of the IBM is presented. The basic IBM is then applied to the even tungsten isotopes and compared with experimental observables associated with the low-lying states. These observable include transition rates, branching ratios, ρ(EO) values, quadrupole moments of the first two excited 2⁺ states, two-neutron separation energies, and isomer and isotope shifts. The results are seen to agree very well with the experimental data. Following the study of the tungsten isotopes an extension of the IBM to describe configuration mixing is presented. This extension is seen to be necessary when there are only a few valence protons or neutrons. In such cases the low-lying energy levels can be built upon more than one configuration. For example, states involving a two-particle-two-hole excitation from the core may occur in the same energy region as states made from only the valence nucleons. The extension of the IBM presented to handle such situations is quite general. A specific example using the light mercury isotopes and the molybdenum isotopes is given. The IBM is then examined from a microscopic point of view, using the generalized seniority scheme. The structure of the bosons of the IBM is given in terms of correlated fermion pairs. Predictions for the IBM parameters are obtained by constructing the zeroth-order image of the corresponding fermion operator. The predictions of a single j-shell approximation are compared with empirical results. In this approximation the valence nucleons are assumed to occupy a single j-shell whose effective j value is chosen so as to reproduce the total occupancy of the valence shell. Next, the predictions of a two non-degenerate j-shell approximation are compared with empirical results. This appoximation appears to be valid in both the 50-82 and the 82-126 neutron shells whose single-particle levels seem naturally to form two sub-shells. The predictions for the IBM parameters dependent on neutron number are seen to be in better agreement with empirically determined values than the predictions for the single j-shell (the proton-number dependent parameters are not treated). Furthermore, the two j-shell calculations reproduce the observed SU(3) or rotational character of the low-lying states of many mid-shell nuclides in the medium-to-heavy mass region. Finally, a brief description of the Interacting Boson-Fermion Model is given. This model is seen to be very successful in describing nuclei with an odd number of protons or neutrons. A calculation of the energy spectrum of the odd tungsten isotopes is presented.

A dissertation submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg, in fulfilment of requirements for the degree of Master of Science. August 11, 2014. / The Z' gauge boson is a hypothetical neutral particle of spin-1 appearing in many theories beyond the Standard Model. In the context of the Z' boson of the Sequential Standard Model in the hadronic decay channel Z' ThadThad, this project investigates improving the sensitivity of the analysis. It is important in the analysis to have high signal e ciency and to be able to distinguish against background processes, thus this project begins with an investigation into new triggers and their combinations that aim to improve the signal e ciency, followed by a study to improve the tau identi cation using tracking. Monte Carlo samples were compared with the data sample for various cut-based variables to investigate which of the variables o er a good discrimination power against the multijet background. The signi cance of each trigger and trigger combinations are shown, as well as the performance of di erent techniques and ideas used to improve the tau identi cation using tracking. Since it is important in this project to be able to reconstruct a tau lepton from its hadronic decay products, this dissertation takes the opportunity to present preliminary results on the study of the light collection uniformity and response in the crack scintillation counters of the ATLAS hadronic tile calorimeter as part of the contribution towards the detector upgrade.

A dissertation submitted in fulfillment of the requirements for the degree of Master of Science in Physics at the University of the Witwatersrand. November 7th, 2016 / The spin-1=2 Kondo model describes an antiferromagnetic exchange interaction between an impurity spin and the spin-density of a Fermi gas. Although the thermodynamics of this system have been resolved, there are still some unanswered questions regarding its spatial features. The spatial region of correlation between the impurity spin and the spin-density of the Fermi gas is referred to as the Kondo screening cloud. For the case of anisotropic couplings, the cloud consists of four distinct components. In this dissertation we use the bosonization technique to derive both an exact numeric and an approximate analytic expression for the forward scattering longitudinal cloud at the Toulouse point. The expressions are then extended to incorporate the effects of a time-independent external magnetic field. The non-magnetic case displays universal scaling behavior, while the addition of an external magnetic field only slightly spoils the scaling in the vicinity of the crossover length (B) K , but remarkably not deep inside or outside the cloud. / MT2017

by Choy Juliet. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1998. / Includes bibliographical references (leaves 142-144). / Text in English; abstract also in Chinese. / by Choy Juliet. / List Of Figures --- p.iii / List of Tables --- p.xxii / Abstract --- p.xxiii / Acknowledgments --- p.xxvi / Chapter 1 --- Introduction --- p.1 / Chapter 2 --- Review On Free Bose Gases --- p.6 / Chapter 2.1 --- 3D Free Bose Gas --- p.6 / Chapter 2.2 --- Bose-Einstein Condensation in Three Dimensions --- p.9 / Chapter 2.3 --- Ideal Bose Gas in Two Dimensions [15] --- p.12 / Chapter 3 --- Bose-Einstein Condensation in a 3D cubic box --- p.15 / Chapter 3.1 --- Effects of boundaries on Bose-Einstein Condensation --- p.15 / Chapter 3.2 --- Bose-Einstein condensation in a 3D cubic box --- p.17 / Chapter 3.3 --- Numerical results for bosons in a 3D cubic box --- p.20 / Chapter 4 --- Bosons in harmonic potentials --- p.25 / Chapter 4.1 --- 3D Isotropic harmonic potential --- p.26 / Chapter 4.2 --- 3D Anisotropic harmonic potentials --- p.32 / Chapter 4.3 --- 2D Harmonic potential --- p.37 / Chapter 4.4 --- ID Harmonic potential --- p.42 / Chapter 5 --- Bosons trapped in highly anisotropic harmonic potentials --- p.47 / Chapter 5.1 --- Two-step Condensation in highly anisotropic harmonic traps --- p.48 / Chapter 5.2 --- The freezing out of the degrees of freedom --- p.51 / Chapter 6 --- Bosons in q-deformed potentials --- p.56 / Chapter 6.1 --- The q-deformed harmonic oscillator --- p.57 / Chapter 6.2 --- Condensation of a Bose gas with the q-deformed harmonic oscillator energy spectrum --- p.60 / Chapter 7 --- Rotational and density related properties of trapped bosons: the formalism --- p.77 / Chapter 7.1 --- Rotational properties of trapped bosons --- p.77 / Chapter 7.2 --- Density related properties of trapped bosons --- p.82 / Chapter 8 --- Rotational and density related properties of trapped bosons: results for harmonic and q-deformed oscillators --- p.88 / Chapter 8.1 --- Rotational property of bosons in harmonic andq-deformed potentials --- p.88 / Chapter 8.2 --- Density related properties of bosons in harmonic and q-deformed potentials --- p.103 / Chapter 9 --- Thermal properties of bosons in the field of a superposition of double-well potentials --- p.121 / Chapter 9.1 --- Numerical study of bosons in the field of a superposition of double- well potentials --- p.121 / Chapter 9.2 --- Low temperature thermodynamics of bosons in a double well po- tential --- p.129 / Chapter 10 --- Conclusion --- p.139

158 p. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Mathematical Physics, 1974

Thesis (M.Sc.). / Written for the Dept. of Physics. Title from title page of PDF (viewed 2008/12/07). Includes bibliographical references.