Un moment dipolaire électrique permanent (EDM) est une propriété fondamentale des systèmes simples comme par exemple l'électron, les atomes/molécules ou le neutron dont l'existence est prédite par le Modèle Standard de la physique des particules (MS) mais qui n'a pas pour l'heure jamais été observée. Cette observable violant la symétrie CP offre la possibilité de relier la physique des particules à l'énigme cosmologique fondamentale de l'asymétrie baryonique de l'Univers observée de nos jours. Produire une telle asymétrie requiert de nouvelles sources/de nouveaux mécanismes de violation de CP, hors MS, qui peuvent être sondés de façon privilégiée par les recherches d'EDM. La sensibilité des expériences EDM actuelles se trouve des ordres de grandeurs au-dessus des prédictions du secteur faible du MS. L'absence de signal, après 60 ans de quête, détermine la limite supérieure la plus forte sur la violation de CP dans le secteur fort du MS et contraint l'espace des phases des modèles de nouvelle physique. A contrario, la mesure d'un EDM non nul dans les années à venir pourra s'interpréter comme le signal d'une physique au-delà du MS évoluant à l'échelle multi-TeV. Dans cette perspective envoûtante, de nombreux nouveaux projets de mesures des EDM ont vu le jour ces dernières années et d'importants efforts sont poursuivis auprès du neutron notamment. Ce manuscrit présente la recherche de l'EDM du neutron menée auprès de l'expérience la plus sensible à ce jour basée à l'Institut Paul Scherrer en Suisse. / A permanent electric dipole moment (EDM) is a fundamental property of simple systems such as the electron, atoms/molecules or the neutron whose amplitude is expected to be non-zero within the Standard Model of particles physics (SM) but which has never been observed so far. This observable violating the CP symmetry offers the opportunity to link particle physics to the fundamental cosmological enigma of the observed baryon asymmetry of the Universe. Such an asymmetry requires new CP violation sources/mechanism beyond the SM, which can be best probed by EDM searches. The current EDM experiments sensitivity is order of magnitude above the weak SM sector predictions. Measuring a null EDM, after a 60 years quest, set the strongest upper limit on the CP violation in the strong SM sector and constrains the new physics models phase space. On the contrary, measuring a non-zero EDM in the coming years can be understood as a signal from physics beyond the SM evolving at a multi-TeV scale. In this haunting perspective, many new EDM projects raised in the last years and important efforts are pursued near the neutron in particular. This manuscript present the neutron EDM search near the most sensitive experiment running at the Paul Scherrer Institute in Switzerland.

Un point crucial pour l'avenir de la Physique de Particules est représenté par la mesure de la masse et des paramètres qui gouvernent l'oscillation du neutrino, qui représentent la preuve de Physique au-delà du Model Standard. Depuis 2011, la valeur élevée de l'angle de mélange θ13 a ouvert la voie à l'étude sur la violation de symétrie CP dans le secteur de neutrinos. La nouvelle d'expérience DUNE (Deep Underground Neutrino Experiment) a un potentiel sans précédent pour effectuer une mesure très précise des paramètres d'oscillation de neutrinos. Les grands détecteurs souterrains nécessaires pour ces mesures sont également un milieu idéal pour la recherche sur la désintégration du proton et sur la détection de neutrinos provenant des supernovæ.Les détecteurs utilisés pour ces expériences sont des Chambres à Projection Temporelle (TPC) dont la cible, très massive, est constituée d'Argon liquide. Ce type de détecteur fournit une très bonne résolution de l'image reconstruite, une excellente résolution en énergie et la possibilité d'identifier les particules. Les interactions de neutrino produisent des particules secondaires qui ionisent l'Argon liquide. Les électrons produits par ionisation dérivent sur de longues distances, sous l'effet d'un champ électrique uniforme, jusqu'à rejoindre l‘anode, équipé pour la détection de la charge. Un signal électrique est alors produit et est utilisé pour la reconstruction 3D de l'interaction primaire. La TPC en double phase liquide-gaz permet l'amplification du signal d'ionisation par des avalanches qui se produisent dans la phase gazeuse, au-dessus du niveau de l'Argon liquide. Cette technique améliore les performances de TPC en augmentant son rapport signal-bruit.Le sujet de cette thèse est la reconstruction et l'analyse de la charge de ionisation dans une TPC à Argon liquide : la mesure de la charge déposée par ionisation fournit des informations sur l'énergie cinétique des particules chargées secondaires produites lors de l'interaction de neutrino. De cette manière, il est possible de reconstruire l'énergie du neutrino entrant, de reconnaître et d'exclure les gerbes électromagnétiques produites par la désintégration du π0, puis d'effectuer l'indentification des particules à partir de la mesure des pertes d'énergie par ionisation.La mesure de l'ionisation implique une connaissance approfondie de la réponse du détecteur et de l'algorithme de reconstruction. Afin d'atteindre cette connaissance nous avons effectué une analyse détaillée des pertes d'énergie simulée en étudiant les divergences entre les connaissances théoriques et la simulation. Ensuite, la simulation de la réponse du détecteur a été étudiée, en examinant les effets qui se produisent au cours de la dérive des charges et les effets liés à la réponse de l'instrumentation électronique. Ces effets systématiques qui affectent l'exactitude de l'algorithme de reconstruction sont alors caractérisés par rapport à la génération de Monte-Carlo.Par la suite, nous montrons comment il est possible d'effectuer la rejection du π0 en étudiant les pertes d'énergie. En mesurant les pertes par ionisation au début d'une gerbe électromagnétique, il est possible de comprendre si elle a été produite par un électron ou par un photon. Cela permet d'exclure le bruit dans la détection des produits d'interaction du neutrino électronique fondamental pour la recherche de la violation de CP.Par l'échantillonnage de la trajectoire d'une particule chargée et en mesurant ses pertes d'énergie, il est possible d'identifier sa nature. Une TPC à Argon liquide est également un milieu idéal pour la recherche de la désintégration du proton, en particulier en regardant certaines chaînes de désintégration exclusives, comme p  K + ν. Dans cette thèse, nous montrons ainsi comment il est possible d'identifier des particules à partir de la mesure des pertes d'énergie, et plus abordons plus précisément l'identification des kaons chargés / This is an important period for High Energy Physics: many recent results, including the Higgs discovery and its characterization, confirm the Standard Model. A crucial point for the future of Particle Physics is the study of neutrino masses and mixing representing the first established evidence of physics beyond the SM. Since 2011, the large value of the ?13 mixing angle opened the way to the investigation of CP violation in the neutrino sector. A next generation long baseline neutrino experiment (DUNE) has unprecedented potential to precisely measure the neutrino oscillation parameters, determine the neutrino mass hierarchy and has a very good chance to discover evidence for CP violation in the leptonic sector. The large underground neutrino detectors needed for this task will also address the search for proton decay and the observation of supernovae neutrinos. Giant Liquid Argon Time Projection Chambers (LAr TPCs) will be employed as neutrino targets and detectors. They provide bubble-chamber quality imaging coupled to excellent energy resolution and particles identification capabilities. Neutrino interactions produce secondary particles, which ionize the liquid argon. The ionization electrons drift for long distances along a uniform electric field until they reach finely segmented and instrumented anodes, producing electrical signals that are used for 3D imaging and analysis of the primary interactions. The dual-phase readout technique foresees the amplification of the ionization signal in avalanches occurring in the gas phase above the liquid argon level. This technique further enhances the performance of the LAr TPC by increasing its signal to noise ratio. The subject of thesis is the ionization charge reconstruction and analysis in the dual-phase LAr TPC: the ionization charges measurement provides information about the kinetic energy of secondary charged particles produced in neutrino interactions. In this way, it is possible to reconstruct the incoming neutrino energy, identify and reject electromagnetic shower generated by photons from pi0 decay and perform particles identification from the measurement of the specific ionization losses.The measurement of the ionization implies a detailed knowledge of the detector response and of the reconstruction algorithm. In order to achieve this knowledge a detailed analysis of the simulated energy losses has been performed by studying the differences between the theoretical knowledge and the simulation

Submitted by Taís Andrade dos Santos (taisandradedossantos@gmail.com) on 2018-08-07T14:32:53Z No. of bitstreams: 1 Dissertação Tais Andrade_versão final_Educação para Ciência.pdf: 3551524 bytes, checksum: df544a318f0bc4e0995aa98fc191ea08 (MD5) / Approved for entry into archive by Minervina Teixeira Lopes null (vina_lopes@bauru.unesp.br) on 2018-08-08T13:22:48Z (GMT) No. of bitstreams: 1 santos_ta_me_bauru.pdf: 3084159 bytes, checksum: 2b2c1e697b5ab7027bd13738d8d0edb2 (MD5) / Made available in DSpace on 2018-08-08T13:22:48Z (GMT). No. of bitstreams: 1 santos_ta_me_bauru.pdf: 3084159 bytes, checksum: 2b2c1e697b5ab7027bd13738d8d0edb2 (MD5) Previous issue date: 2018-02-19 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Esta pesquisa de mestrado tem o objetivo de investigar o processo de reestruturação curricular de um curso de licenciatura em Física para o atendimento a Deliberação CEE nº 111/2012 e a preparação para a Resolução CNE/CP nº 02/2015. A pesquisa se mostra relevante não apenas para mapear as alterações na grade curricular do curso, de acordo com a legislação, mas principalmente por conhecer as concepções dos gestores, professores formadores e discentes. Esse estudo de caso foi delineado a partir da seguinte questão de pesquisa: “Quais as concepções de Docentes, Gestores e Discentes do curso de Licenciatura em Física sobre as contribuições das modificações curriculares para a formação dos futuros professores?” e com os seguintes objetivos específicos: Conhecer e analisar os documentos oficiais que propõem as modificações no currículo; construir um instrumento de análise argumentativa, por meio das categorias de Toulmin, para que possamos ter uma visão global dos prós e contras do novo currículo pela visão dos sujeitos; analisar/inferir as contribuições do novo currículo para a formação de professores (em relação ao currículo anterior), ou seja, refletir sobre o perfil dos alunos egressos do curso considerando também as mudanças que ocorreram com a nova reestruturação implantada para os alunos ingressos no ano de 2018. Os métodos técnico-instrumentais utilizados foram: análise estrutural de conteúdo material; revisão bibliográfica, análise de documentos, entrevista e questionários analisados através do referencial teórico metodológico de análise da argumentação dos sujeitos. Os referenciais teóricos metodológicos que fundamentaram a pesquisa foram o Padrão de Argumentação de Toumin (TAP) para as concepções dos sujeitos e para as relações de currículo propostos por Apple. Como principais resultados obtidos nesse trabalho temos que apesar do perfil formativo da legislação apontar para uma racionalidade prática com uma estreita relação entre a teoria e a prática, a concepção dos docentes sobre a formação inicial prioriza “saber o conteúdo da Física”, relacionando a prática docente na formação inicial apenas às disciplinas pedagógicas. O processo de reestruturação neste estudo de caso foi realizado de modo verticalizado, apesar de parecer um discurso repetitivo de verticalização na adequação do currículo, os gestores e docentes neste estudo de caso demonstraram que o processo foi realizado apenas para o cumprimento burocrático das deliberações, de modo que os docentes evitaram ao máximo passar pelo processo. Além da implantação da diretriz causar mudanças no estilo de ensino do professor formador, em relação às concepções dos discentes, docentes e dos gestores sobre a reestruturação do currículo; um dos traços mais marcantes é a dicotomia entre o saber dos conteúdos de Física e didática, essa dicotomia aparece na imposição da deliberação CEE nº 111/2012, que ao assegurar uma carga horária para as disciplinas pedagógica nas licenciaturas, causa na postura dos sujeitos o discurso de que a alteração é interessante à formação dos futuros professores, desde que não altere a carga horária das disciplinas de Física. Por fim como contribuições deste trabalho compreende-se que é imprescindível que os currículos devem ser reformulados não apenas por documentos legais, mas que o processo de reflexão da formação inicial docente deve ser contínuo e repensado pelos próprios professores formadores e gestores. / This master's research aims to investigate the process of curricular restructuring of a degree in Physics for compliance with CEE resolution 111/2012 and the preparation for CNE / CP Resolution 02/2015. The research is relevant not only to map the changes in the course curriculum of the course, according to the legislation, but mainly to know the conceptions of managers, teachers and students. This case study was delineated from the following research question: "What are the conceptions of Teachers, Managers and Students of the Licentiate in Physics course on the contributions of curricular modifications to the training of future teachers?" And with the following specific objectives : To know and to analyze the official documents that propose the modifications in the curriculum; to construct an instrument of argumentative analysis, through Toulmin's categories, so that we can have a global view of the pros and cons of the new curriculum by the subjects' view; to analyze / infer the contributions of the new curriculum for teacher training (in relation to the previous curriculum), that is, to reflect on the profile of the students who graduated from the course, also considering the changes that occurred with the new restructuring implemented for students in the year of 2018. The technical-instrumental methods used were: structural analysis of material content; bibliographic review, document analysis, interview and questionnaires analyzed through the theoretical methodological reference of the analysis of the subjects' arguments. The theoretical methodological references that supported the research were the Toulmin Argumentation Standard (TAP) for the subjects' conceptions and for the curriculum relations proposed by Apple. As the main results obtained in this work we have that although the training profile of the legislation points to a practical rationality with a close relationship between theory and practice, the teachers' conception about initial training prioritizes “to know the content of Physics”, relating the teaching practice in the initial training only to the pedagogical disciplines. The restructuring process in this case study was carried out vertically, although it seems to be a repetitive discourse of verticalisation in the adequacy of the curriculum, the managers and teachers in this case study demonstrated that the process was carried out only for the bureaucratic fulfillment of the deliberations, of so that teachers avoided the process as much as possible. In addition to the implementation of the directive cause changes in the teaching style of the teacher trainer, in relation to the conceptions of the students, teachers and managers on the restructuring of the curriculum; one of the most striking features is the dichotomy between the knowledge of the contents of Physics and didactics, this dichotomy appears in the imposition of the CEE resolution No. 111/2012, which, by securing an hourly load for the pedagogical disciplines in the degrees, discourse that the change is interesting to the training of future teachers, as long as it does not change the workload of the Physics disciplines. Finally, as contributions of this work it is understood that it is imperative that curricula must be reformulated not only by legal documents, but that the process of reflection of initial teacher education must be continuous and rethought by the teacher trainers themselves and managers.

No description available.

Submitted by Maike Costa (maiksebas@gmail.com) on 2017-07-05T14:50:01Z No. of bitstreams: 1 arquivototal.pdf: 3897113 bytes, checksum: 13b1bc4f67b2b3d6ab8fad34190f7c20 (MD5) / Made available in DSpace on 2017-07-05T14:50:01Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 3897113 bytes, checksum: 13b1bc4f67b2b3d6ab8fad34190f7c20 (MD5) Previous issue date: 2017-03-30 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / In this thesis we study the phenomenological consequences of several CP-violating structures that could arise in the Standard Model effective field theory framework. Focusing on operators involving electroweak gauge and/or Higgs bosons, we derive constraints originating from Run I LHC data. We then study the capabilities of the present and future LHC runs at higher energies to further probe associated CP-violating phenomena and we demonstrate how differential information can play a key role. We consider both traditional four-lepton probes of CP-violating in the Higgs sector and novel new physics handles based on varied angular and non-angular observables. / Nesta tese é estudado as consequências fenomenológicas de diversas estruturas que violam a simetria CP, surgidas no contexto do modelo padrão efetivo. Focando nos operadores que envolvem os bósons de calibre e o Higgs, estabelecemos vínculos provenientes dos dados do RUN I do LHC. Em seguida, é estudada a capacidade do RUN I e de futuros RUNs do LHC em sondar os fenômenos associados à violação de CP e é demonstrado como as informações provenientes das distribuições diferencias podem desempenhar um papel chave para determinação destes vínculos. Para sondar efeitos físicos de violação de CP, consideramos tanto as sondagens tradicionais utilizando o canal de decaimento do Higgs em 4 léptons assim como novos observáveis angulares e cinemáticos empregados em diferentes canais de produção e decaimento do Higgs.

Neste trabalho estudamos algumas propriedades do espaço das funções contínuas munido da topologia da convergência pontual. Começamos estudando o espaço Cp(X) de forma geral, verificando que propriedades topológicas principais valem em Cp(X), usando teoremas de dualidade entre X e Cp(X). Em seguida estudamos a relação da estrutura topológica de X e a estrutura algébrica e topológica de Cp(X), onde o Teorema de Nagata é fundamental. Observamos algumas propriedades de X que são preservadas por l-equivalência ou t-equivalência, ou seja, que são determinadas pela estrutura linear topológica, ou pela estrutura topológica de Cp(X), respectivamente. Por último estudamos as condições para que Cp(X) seja um espaço de Lindelöf. Concluímos com a prova de Okunev de que o número de Lindelöf de Cp(X) é igual ao número de Lindelöf de Cp(X)xCp(X), para espaços fortemente zero-dimensionais X. / In this work we study some properties of the space of continuous functions endowed with the topology of pointwise convergence. We begin by studying the space Cp(X) in general terms, verifying that the main topological properties are valid in Cp(X), using duality theorems between X and Cp(X). Next we study the relationship between the topological structure of X and the algebraic as well as topological structure of Cp(X), in which the Nagata theorem theorem is essential. We observe some properties of X, which are preserved by l-equivalence or t-equivalence, i.e., which are respectively determined either by the linear topological structure of Cp(X) or by its topological one. Finally we study in which conditions Cp(X) is a Lindelöf space. We conclude with the proof of Okunev that the Lindelöf number of Cp(X) is equal to the Lindelöf number of Cp(X)xCp(X), for strongly zero-dimensional spaces X.

Orientador: Orlando Luis Goulart Peres / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Física Gleb Wataghin / Made available in DSpace on 2018-08-23T16:45:26Z (GMT). No. of bitstreams: 1 Gaydutschenko_Larissa_M.pdf: 776013 bytes, checksum: dded3e977e716b07101df7cb392a6b94 (MD5) Previous issue date: 2013 / Resumo: O fenômeno de oscilação de neutrinos, já experimentalmente observado, só pode ser explicado se a massa dos neutrinos for diferente de zero. No entanto, até pouco tempo atrás, acreditava-se que neutrinos não tivessem massa. O Modelo Padrão das partículas elementares ainda não é capaz de descrever a natureza massiva dos neutrinos, de forma que as matrizes de mistura para léptons (entre autoestados de gauge e autoestados de massa), análogas às matrizes de mistura de quarks, ainda não podem ser encontradas. Através de uma pequena extensão do Modelo Padrão, é possível descrever uma física que leva em conta essas massas e que, portanto, nos fornece essas matrizes de mistura. Essa extensão trata-se de nada mais que o acréscimo de uma nova partícula ao modelo, um lépton neutro que não interage por força fraca. Essa partícula é chamada de neutrino estéril. Portanto, acrescentando um ou mais neutrinos estéreis ao Modelo Padrão posso obter a matriz de mistura para léptons e, consequentemente, contar o número de parâmetros físicos que ela possui. O interesse em contar esses parâmetros reside no fato de que encontrar o número de fases complexas presentes na matriz de mistura é equivalente a encontrar o número de fases de violação de simetria conjugação de carga e paridade (CP) para léptons. Em 1967, o físico russo Andrei Sakharov propôs uma forma de explicar a assimetria bariônica (matéria-antimatéria) partindo de um estado simétrico. Para isso, algumas condições precisariam ser respeitadas pela física do universo. Uma dessas condições é que exista na natureza uma fonte de violação CP. Procurar essa violação em léptons foi o objetivo deste trabalho. Assim, foi possível obter a matriz de mistura para léptons estendendo o modelo padrão pela adição de um neutrino estéril e levando em conta o caso geral de n famílias de léptons. Uma vez tendo encontrado a matriz de mistura, fizemos a contagem dos parâmetros. Além abranger os cálculos usados para encontrar o número de fases complexas damatriz, a dissertação apresenta uma breve introdução à teoria quântica de campos, a simetrias discretas e ao mecanismo de quebra espontânea de simetria, conceitos necessários para o entendimento do trabalho realizado / Abstract: The neutrino oscillation phenomenum, already experimentally observed, can only be explained if neutrino masses are different from zero. However, till recently, it was believed that neutrinos were massless. The Standard Model of elementary particles is yet not able to describe the massive nature of neutrinos, such that the lepton mixing matrix (between gauge eigenstates and mass eigenstates), analogous to the quark mixing matrix, can still not be found. Through a small extension of the Standard Model, it is possible to describe physics that take into account these masses and, therefore, provides us with these mixing matrices. This extension is nothing but the addition of a new particle, a neutral lepton that does not interact through weak force. This particle is called sterile neutrino. So, by adding one or more sterile neutrinos to the Standard Model, I can get the lepton mixing matrix and consequently count the number of physical parameters that it presents. The interest in counting these parameters resides in the fact that finding the number of complex phases in the mixing matrix is equivalent to finding the number of charge conjugation-parity (CP) violation for leptons. In 1967, the Russian physicist Andrei Sakharov proposed a way to explain the baryonic asymmetry (matter-antimatter) beginning with a symmetric state. For that to work some conditions needed to be respected by the universe physics. One of them is that there must exist in nature a source of CP violation. Looking for that source as the leptonic sector of the particle physics was the goal of this project. And finally it was possible to get the lepton mixing matrix extending the standard model by the addition of one sterile neutrino and taking into account the general case of n lepton families. Once we got the mixing matrix, we counted the physical parameters. Besides presenting all the calculation used for finding the number of complex phases in the matrix, this thesis presents a brief introduction to quantum field theory, discrete symmetries and the spontaneous symmetry breaking mechanism, all of these concepts being necessary for the understanding of the work accomplished / Mestrado / Física / Mestra em Física

Le titane et ses alliages sont devenus des matériaux incontournables dans l'aéronautique, le domaine biomédical et l'industrie chimique et ce depuis le début des années 1950 en raison de haut rapport résistance/poids, une excellente biocompatibilité et une bonne résistance à la corrosion. La structure hexagonale du titane conduit à une anisotropie intrinsèque, due à la configuration atomique particulière et à une anisotropie extrinsèque, due à une texture marquée produite lors de leur élaboration. Le but de cette étude est d'améliorer la compréhension des mécanismes de déformation (glissement et maclage) dans le titane conduisant à cette anisotropie extrinsèque. Une technique d’essais interrompus in situ en MEB / EBSD a été utilisée lors la déformation plastique d’un alliage de titane T40 commercialement pur afin de suivre l'évolution de l'orientation cristalline et de la morphologie des grains au cours de la déformation sous différents types de chargement (traction, laminage, cisaillement). Cette technique permet de suivre l’apparition du maclage, la croissance et la forme des macles, l’interaction des variants de macles avec les grains voisins. Le Facteur de Schmid, l’orientation cristallographique, l'énergie de déformation plastique, et la déformation localisée liée à l’accommodation ont été calculés pour analyser l'activation du maclage, la croissance des macles, et la sélection de variant de macle. Des variants de macles avec un faible facteur Schmid, facteur qui exprime la force appliquée externe sur le plan de maclage et le long de la direction de maclage, ont été observés. Cela indique le facteur Schmid n'est pas très approprié pour prédire le maclage. Une règle de sélection de variant de maclage a été proposée sur la base de la consommation maximale d'énergie plastique. L'énergie plastique (on suppose le matériau comme étant rigide parfaitement plastique) consommée est calculée de la façon suivante : la déformation que produit chaque variant est exprimée du repère cristal au repère macroscopique ; la contrainte suit une loi de type Hall Petch, le diamètre des grains est alors défini comme la longueur maximale que peut prendre chaque variant dans le grain. Le variant qui consomme le plus d’énergie est activé le premier. Ces calculs sont en bon accord avec l'observation expérimentale : Les variants de macles sélectionnés étaient ceux conduisant à une consommation maximale de l'énergie plastique. Le libre parcours que peut prendre chaque variant est un critère pertinent puisque cela permet d’expliquer les différences observées dans un grain équiaxe ou un grain allongé en terme de nombre de variants présents et croissance des macles. Les essais interrompus in – situ montrent des chaines de macles ou paires de macles (propagation dans 2 ou plusieurs grains voisins). Une macle est activée en premier dans un grain, avec sa croissance, elle impose un champ de contrainte et un champ de déformation dans les grains voisins ce qui peut activer une macle dans les grains voisins. Les paires de macles ont un paramètre de Luster - Morris relativement élevé, ce qui traduit une bonne compatibilité entre les macles et une propagation facile de macle dans les grains voisins. Par une simple transformation du tenseur gradient de déplacement du variant utilisé dans le grain considéré on obtient la déformation imposée dans le grain voisin. Le variant de macle dans ce grain voisin pouvant accommoder le plus facilement la déformation imposée sera activé. Ceci montre que la déformation locale peut influencer l’activation et la sélection de variant de macle / Titanium and its alloys have become backbone materials for aerospace, biomedical field and chemical industries since the early 1950s because of the high strength-weight ratio, excellent biocompatibility, and good corrosion resistance. The hexagonal structure of titanium leads to an intrinsic anisotropy of the particular atomic configuration and extrinsic anisotropy of the texture to a product marked in their elaboration. The purpose of this study is to improve understanding of the deformation mechanisms (slip and twinning) in the titanium leading to the extrinsic anisotropy. Technical testing interrupted in situ SEM / EBSD was used in the plastic deformation of a commercially pure titanium alloy T40 to follow the crystal orientation and morphology of the grains during deformation under different types of loading (tension, rolling). This technique allows following the occurrence of twinning, growth and shape of the twins, the interaction of the twin variants with neighboring grains. Schmid factor, crystallographic orientation, plastic deformation energy, and localized strain accommodation were calculated to analyze the twin activation, the twin growth, and twin variant selection. Twinning variant with relatively low global Schmid factor, which resolves the externally applied force onto the twinning plane and along the twinning direction, were observed. That indicates the global Schmid factor is not very appropriate to predict twinning. A twinning variant selection rule was proposed based on the maximum plastic energy consumption. The plastic energy ( the material is assumed to be perfectly rigid plastic) consumed is calculated as follows: the deformation produced by each variant is expressed from crystal frame to macro frame; stress follows a Hall Petch type rule, the grain diameter is then defined as the maximum length that can take each variant in the grain. The variant which can consume the maximum of the externally imposed energy is expected to twin first. The calculation results show good agreement with the experimental observation: The selected twin variants were the one leading to maximum plastic energy consumption. The variant free path length relevant criterion so indicates the reason why the equiaxed grains and elongated grains have the difference in twin variant number and twinning variant growth. The interrupted in-situ investigation shows that the twin chains or twin pairs observed in this work are a sequential twinning behavior. A twin activated first, with its growth, it imposes a strain field and a stress field into its neighboring grains and possibly stimulate a twin in the neighboring grain. The twin pairs show a good alignment with a relatively high Luster-Morris parameter, which is a measure of the compatibility of twinning systems through a grain boundary. By the displacement gradient tensor transformation, the imposed strain into the neighboring grain was obtained. The twinning variant which can better accommodate the imposed strain can be activated. It indicates that the local strain can influence the twinning activation and variant selection

Ce document de thèse décrit la recherche des désintégrations en trois corps des mésons beaux neutres qui contiennent un KS ou un pi 0 dans l'état final. Ces événements sont reconstruits au moyen du spectromètre LHCb installé auprès du collisionneur proton-proton LHC, sis au Cern à Genève. La phénoménologie des ces modes est riche et couvre la possibilité de mesurer tous les angles du triangle d'Unitarité de la matrice Cabibbo-Kobayashi-Maskawa (CKM) qui décrit les amplitudes de transition par courant chargé faible entre quarks. Une illustration portant sur la mesure de l'angle gamma est développée dans ce document plus en détail. L'accélérateur LHC et les éléments utiles du spectromètre LHCb sont rapportés en mettant l'accent sur le travail conduit au cours de cette thèse sur l'étalonnage et l'alignement du détecteur de pieds de gerbe du calorimètre électromagnétique. Nous avons construit une méthode de calibration du détecteur au moyen de particules qui le traversent au minimum d'ionisation. Les résultats et les performances de ces calibrations sont discutées. Une méthode de discrimination des pi 0 et des photons de haute énergie est présentée, bénéficiant des mesures des caractéristiques des cascades électromagnétiques dans le PreShower et le calorimètre. Ces informations sont combinées dans une analyse multivariable. La stratégie de contrôle des performances du discriminateur directement à partir des données est discutée et cet outil est appliqué à la recherche des états finals B to hh pi 0. Une recherche similaire des modes de désintégration B{d,s} to KShh, où h peut être un pion ou un kaon chargé a été conduite. Ce mode de désintégration permet de mesurer la phase faible du mélange des mésons Bd ou Bs et la comparaison de ces déterminations avec celles extraites des modes charmonia peut permettre de mettre en évidence une phase faible au-delà du Modèle Standard dans l'amplitude de désintégration. La première étape de cette analyse consiste à établir les signaux des modes non encore observés B{s} to KShh. Ce travail exploratoire présente la première observation du mode B{s} to KSK pi. / This thesis describes an exploratory work on three-body charmless neutral $B$ mesons decays containing either a $K_S$ or a $\pi^0$. The events are reconstructed with the LHCb spectrometer installed at Cern (Geneva, CH) recording the proton-proton collisions delivered by the Large Hadron Collider (LHC). The phenomenology of such modes is rich and covers the possibility to measure all angles of the unitarity triangle linked to the Cabibbo-Kobayashi-Maskawa (CKM) matrix. The single example of the $\gamma$ measurement is explored in this document. The LHC accelerator and the most relevant sub-detector elements of the LHCb spectrometer are described in details. In particular, emphasis is given to the calorimetry system for which the calibration and alignment of the PreShower (PRS) of the electromagnetic calorimeter has been performed. We used particles at minimum ionisation deposit for such a task. The calibration results until year 2011 are reported as well as the method of the PS alignment with respect to the tracking system of the spectrometer. A method to discriminate high energy $\pi^0$ and photon is introduced, based on electromagnetic cascade information combined into a multivariate analysis. The strategy to evaluate the performance is given and the tool is applied to the exploratory search of $B \to hh\pi^0$ final states. Additionally, we conducted a similar search for the modes $B_{d,s} \to K_Shh$, where $h$ can be either a charged kaon or a pion. The physics reach of such modes lies in the possibility of measuring the $\beta$ and $\beta_s$ CKM angles to be compared to their charmonia extraction. Differences in between these two determinations can be the sign of New Physics. The first step of this search is to establish the unobserved modes $B_{s} \to K_Shh$. We report in a fifth of the data 2011 statistics the first observation of the decay channel $B_{s} \to K_SK\pi$.

Orientador: Pedro Cunha de Holanda / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Física Gleb Wataghin / Made available in DSpace on 2018-08-31T06:55:32Z (GMT). No. of bitstreams: 1 Sato_EduardoAkio_M.pdf: 2319995 bytes, checksum: fc82384c799d5812bf14a71fe2723e2d (MD5) Previous issue date: 2016 / Resumo: Nesta dissertação analiso como uma classe de modelos sugeridos para acomodar neutrinos massivos no modelo padrão, os assim chamados mecanismos seesaw, podem também resolver o problema de assimetria bariônica no universo. Os requisitos mínimos para uma geração dinâmica bem sucedida de assimetria bariônica, conhecidos como condições de Sakharov, são: não conservação de número bariônico, violação de simetria CP e ausência de equilíbrio térmico. Para mostrar que mecanismos seesaw respeitam estas regras, reviso alguns tópicos como: a violação de número bariônico através do processo de sphalerons, a teoria de violação de CP através de invariantes de base fraca e a mecânica estatística de não equilíbrio através da equação de Boltzmann. Como exemplo considero um cenário de mecanismo seesaw tipo I (3+3) com massas de neutrinos estéreis altamente hierárquicas. A assimetria observada impõe um limite inferior na massa dos neutrinos estéreis ($M_1 \geq 8.4 \times 10^{8} \; \text{GeV}$) e um limite superior na massa dos neutrinos ativos ($m_1 < 0.11 \; \text{eV}$), consistente com limites previamente obtidos na literatura / Abstract: In this dissertation I analyse how a class of models suggested to accommodate massive neutrinos in the standard model, the so-called seesaw mechanisms, can also solve the baryon asymmetry of the universe problem. The minimal requisites to a successful dynamical generation of baryon asymmetry, known as Sakharov's conditions, are: Non-conservation of baryon number, violation of CP symmetry and absence of thermal equilibrium. To show that seesaw mechanisms respect those rules, I review some topics such as: the standard model baryon non-conservation via sphalerons process, the theory of CP violation via weak-basis invariants and non-equilibrium statistical physics via Boltzmann equation. As a example I consider a type I (3+3) seesaw mechanism scenario with highly hierarchical sterile neutrino masses and the observed asymmetry impose a lower bound in the sterile neutrino masses ($M_1 \geq 8.4 \times 10^{8} \; \text{GeV}$) and a upper bound in the active neutrino masses ($m_1 < 0.11 \; \text{eV}$), consistent with limits previously obtained in the literature / Mestrado / Física / Mestre em Física / 1370441/2014 / CAPES