Orientador: Marcelo Moraes Guzzo / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Física Gleb Wataghin / Made available in DSpace on 2018-08-24T07:13:46Z (GMT). No. of bitstreams: 1 Costa_RafaelNobertoAlmeidada_M.pdf: 2184656 bytes, checksum: 96104bbac452f3b0ec1bab401b55bf0a (MD5) Previous issue date: 2014 / Resumo: Apresentamos neste trabalho um review descrevendo a oscilações de neutrinos quando é levado em conta a violação da simetria de carga paridade (CP). Por conta disso abordaremos a origem da violação de CP no Modelo Padrão das Partículas Elementares, desde a sua descoberta no sistema dos mésons káons neutros (K°) ,até a sua inclusão dentro do Modelo Padrão, a qual foi desenvolvida por Kobayashi e Maskawa. Depois de entendermos a violação de CP passamos a tratar das oscilações de neutrinos e como esta violação é incluída no modelo. Abordamos o modelo utilizando os dados mais recentes dos parâmetros para as oscilações de neutrinos, incluindo a recente medição do ângulo de mistura ?13. Utilizando estes dados e os resultados obtidos a partir do modelo de oscilações de neutrinos inferimos um limite para a fase de violação de CP, dado por nós como sendo ?CP= 19 ^{+19°}_{-9°} com 1? de C.L. / Abstract: In this work was make a review describing the neutrino oscillations when is taken in account the charge parity symmetry violation (CP). Because of that we will approach the origin of CP violation in Standard Model of Elementary Particles, since its discovery in the neutral kaons meson system (K°), until its inclusion within the Standard Model, made by Kobayashi and Maskawa. After we understand the CP violation we treat the neutrino oscillations and how this violation is included in the model. We approach the model using the most recent data of the parameters from neutrino oscillations, including the recent data measured to the mixing angle ?13. Utilizing this data, and the data obtained from the model of neutrino oscillation, we infer a limit to the CP violation phase, given by us as being ?CP= 19^{+19°}_{-9°} with 1? of C.L. / Mestrado / Física / Mestre em Física

Since the construction of the IceCube Neutrino Observatory was completed in 2010, many amazing discoveries have been made in the field of neutrino physics. Recently a neutrino event has been linked to an blazar-type active galactic nucleus source, bringing us one step closer to understanding the production of high-energy extragalactic neutrinos and ushering in a new era of multimessenger astronomy. This was found by linking the neutrino event to one of the Fermi Collaboration’s gamma ray sources which had a blazar counterpart. The quest to link other neutrino events to AGN (active galactic nuclei) sources through collaboration with the Fermi Large Area Telescope has turned up some interesting candidates. The fact that some of these potential sources are not blazars is curious and, although unconfirmed as neutrino sources, these objects merit further investigation due to their unusual nature.

No description available.

Le mécanisme permettant d’expliquer l’origine de la masse des neutrinos demeure, encore aujourd’hui, un mystère complet dont la résolution est susceptible de modifier considérablement la structure du modèle standard en physique des particules élémentaires. Dans la littérature, plusieurs candidats potentiels sont donc proposés afin de combler cette lacune et, ainsi, faire la lumière sur certaines des propriétés les plus étranges des neutrinos. Parmi ceux-ci, les mécanismes seesaw de type I, II et III constituent sans doute les approches les plus attrayantes et les plus étudiées. Cependant, bien que ces mécanismes offrent un cadre de travail simple et élégant pour expliquer la faible masse des neutrinos (l’ordre de grandeur), ceux-ci n’offrent aucune prédiction sur les paramètres fondamentaux caractérisant le phénomène d’oscillation, soit les angles de mélange, les phases complexes et la hiérarchie des masses. Afin d’obtenir des prédictions concrètes sur la phénoménologie des neutrinos, certaines hypothèses de travail supplémentaires doivent donc être formulées pour contraindre la structure des matrices de masse obtenue. Dans ce travail, l’hypothèse anarchique propre au secteur des neutrinos est adoptée. Les matrices de masse générées par les trois mécanismes seesaw dans la limite des basses énergies sont traitées dans le contexte d’une théorie de matrices aléatoires, ce qui permet de définir et d’analyser de nouveaux ensembles matriciels aléatoires appelés ensembles seesaw. Un cadre théorique unifié est donc présenté pour la construction de ces ensembles. Grâce au formalisme élaboré, qui repose sur les outils traditionnels relevant de la théorie des matrices aléatoires, les densités de probabilité jointes caractérisant ces ensembles sont obtenues de façon analytique. Une étude détaillée de leurs propriétés est alors réalisée, ce qui permet d’extraire les tendances dominantes propres à ces mécanismes de masse et d’analyser leurs conséquences pour le secteur des neutrinos du modèle standard étendu. En ce qui concerne le spectre de masse, les résultats obtenus indiquent que les mécanismes seesaw de type I et de type III sont plus adéquats pour reproduire les observations expérimentales. De plus, une forte préférence pour la différence de masses associée à la hiérarchie normale est observée. En contrepartie, il est également démontré que pour une différence de masses donnée entre les trois générations, toutes les permutations des masses sont équiprobables, ce qui rend hors de portée toute prédiction concernant la hiérarchie du spectre (normale ou inverse) sous l’hypothèse anarchique. En ce qui concerne les variables du groupe de symétrie (les angles de mélange et les phases complexes), on constate, d’une part, que la notion de mélange quasi-maximal est naturellement favorisée et, d’autre part, que la matrice PMNS peut être décrite comme une matrice unitaire générique tirée au hasard d’un ensemble matriciel caractérisé par la mesure de Haar du groupe de Lie correspondant. Par ailleurs, il est également démontré que ces conclusions sont indépendantes du mécanisme de masse considéré. / The neutrino mass generation mechanism remains, to this day, a complete mystery which is likely to play an important role in understanding the foundations of the Standard Model of particle physics. In an effort to fill this gap and, ultimately, shed some light on some of the most intriguing properties of neutrinos, many theoretical models are proposed in the literature. Among the many candidates, the type I, type II and type III seesaw mechanisms may very well be the most attractive and the most studied propositions. However, despite the fact that these mechanisms provide a simple and elegant framework for explaining the smallness of neutrino masses (the order of magnitude), no prediction can be made on the fundamental parameters governing neutrino oscillations (the mixing angles, the CP-violating phases and the mass differences). Thus, to obtain concrete results regarding neutrino phenomenology, additional working assumptions must be made in order to constrain the structure of the corresponding mass matrices. In this work, the anarchy hypothesis relevant to the neutrino sector is investigated. The mass matrices generated by the three seesaw mechanisms in the low-energy limit are studied within the framework of random matrix theory, which leads to the development and the analysis of the seesaw ensembles. A unified and precise theoretical formalism, based on the usual tools of random matrix theory, is presented for the construction of these new random matrix ensembles. Using this formalism, the joint probability density functions characterizing these ensembles are obtained analytically, thus paving the way for a detailed study of their properties. This study is then carried out, revealing the underlying trends in these ensembles and, thereby, offering a thorough analysis of their consequences for the neutrino sector of the seesaw-extended Standard Model. Regarding the mass spectrum, it is found that the type I and type III seesaw mechanisms are better suited to accommodate experimental data. Moreover, the results indicate a strong preference for the mass splitting associated to normal hierarchy. However, since all permutations of the masses are found to be equally probable for a particular mass splitting between the three generations, predictions concerning the hierarchy of the mass spectrum (normal or inverted) remains out of reach in the framework of anarchy. Regarding the group variables (the mixing angles an CP-violating phases), it is found that near-maximal mixing is naturally favored by these ensembles and, that the PMNS matrix can be described as a generic unitary matrix drawn at random from a matrix ensemble characterized by the Haar measure of the corresponding Lie group. Furthermore, these conclusions are found to be independent of the mass mechanism considered.

[ES] Los neutrinos de alta energía son partículas esquivas: no tienen carga, tienen una sección transversal de interacción muy pequeña con la materia ordinaria y su masa es extremadamente pequeña. Los neutrinos son una sonda importante en el estudio del origen de los rayos cósmicos, y también, siguiendo algunos modelos de la física más allá del modelo Stardard, pueden producirse a partir de la propagación de partículas del modelo estándar producidas por la aniquilación de la materia oscura. En el último siglo, se han desarrollado muchos enfoques nuevos en la física de astropartículas, tratando de resolver los enigmas no resueltos del Universo, como el origen de los rayos cósmicos y la existencia de la materia oscura. Entre los diferentes experimentos destacan, sin duda, los telescopios de neutrinos. Los telescopios de neutrinos, consistentes en un gran volumen de un medio transparente monitorizado por sensores ópticos para detectar luz de Cherenkov, pueden detectar neutrinos de alta energía de fuentes galácticas o extragalácticas, y también pueden usarse para el estudio de las propiedades de los neutrinos. ANTARES y su sucesor KM3NeT son dos telescopios de neutrinos ubicados en el mar Mediterráneo. El telescopio ANTARES empezó a estar operativo en 2007 y ha tomado datos de forma casi continua hasta principios de 2022. KM3NeT, aprovechando la experiencia de ANTARES, pretende ser el telescopio de neutrinos más sensible de la próxima generación de detectores. Esta tesis presenta mis contribuciones en ambos detectores. En concreto, la parte técnica del trabajo se ha desarrollado en colaboración con KM3NeT. Está dedicado al estudio de los datos de los sensores de orientación instalados en los módulos de detección ópticos de KM3NeT: desde su calibración antes del despliegue en el mar hasta el análisis de sus datos in situ. Estos sensores permiten una monitorización de los movimientos de los elementos detectores en el mar. Por otro lado, en colaboración con ANTARES se ha desarrollado un análisis de física relacionado con la búsqueda de la aniquilación de la materia oscura en el Sol analizando trece años de datos. Se han obtenido nuevos límites superiores para los flujos de neutrinos y antineutrinos a partir de la aniquilación de materia oscura en el Sol, y a partir de estos, se han derivado límites superiores a la sección eficaz de dispersión de Materia Oscura - Nucleón. Estos resultados mejoran en un factor dos los resultados anteriores de ANTARES y son competitivos con respecto a otros experimentos. / [CA] Els neutrins d'alta energia són partícules esquives: no tenen càrrega, tenen una secció transversal d'interacció molt petita amb la matèria ordinària i la massa és extremadament petita. Els neutrins són una sonda important en l'estudi de l'origen dels raigs còsmics, i també, seguint alguns models de la física més enllà del Model Stardard, es poden produir a partir de la propagació de partícules del model estàndard produïdes per l'aniquilació de la matèria fosca. A l'últim segle, s'han desenvolupat molts enfocaments nous a la física d'astropartícules, tractant de resoldre els enigmes no resolts de l'Univers, com l'origen dels raigs còsmics i l'existència de la matèria fosca. Entre els diferents experiments destaquen, sens dubte, els telescopis de neutrins. Els telescopis de neutrins, consistents en un gran volum d'un medi transparent monitoritzat per sensors òptics per detectar llum de Cherenkov, poden detectar neutrins d'alta energia de fonts galàctiques o extragalàctiques, i també es poden utilitzar per a l'estudi de les propietats dels neutrins. ANTARES i el seu successor KM3NeT són dos telescopis de neutrins ubicats al mar Mediterrani. El telescopi ANTARES va començar a estar operatiu el 2007 i ha pres dades de forma gairebé contínua fins a principis del 2022. KM3NeT, aprofitant l'experiència d'ANTARES, pretén ser el telescopi de neutrins més sensible de la propera generació de detectors. Aquesta tesi presenta les meves contribucions a tots dos detectors. Concrètement, la part tècnica del treball s'ha desenvolupat en col·laboració amb KM3NeT. Està dedicat a l'estudi de les dades dels sensors d'orientació instal·lats als mòduls de detecció òptics de KM3NeT: des del calibratge abans del desplegament al mar fins a l'anàlisi de les seves dades in situ. Aquests sensors permeten una monitorització dels moviments dels elements detectors al mar. D'altra banda, en col·laboració amb ANTARES s'ha desenvolupat una anàlisi de física relacionada amb la recerca de l'aniquilació de la matèria fosca al Sol analitzant tretze anys de dades. S'han obtingut nous límits superiors per als fluxos de neutrins i antineutrins a partir de l'aniquilació de matèria fosca al Sol, i a partir d'aquests, s'han derivat límits superiors a la secció eficaç de dispersió de Materia Fosca - Nucleó. Aquests resultats milloren en un factor dos els resultats anteriors de ANTARES i són competitius respecte a altres experiments. / [EN] High energy Neutrinos are elusive particles: they are chargeless, have a very small cross section with ordinary matter and their mass is extremely small. Neutrinos are an important probe in the study of the origin of cosmic rays but also, following some models of physics Beyond the Standard Model, they can be produced from the decay of Standard Model particles produced by dark matter annihilation. In the last century, many new approaches have been developed in astroparticle physics, trying to solve the unsolved puzzles of the Universe such as the origin of Cosmic Rays and the existence of Dark Matter. Among the many experiments, neutrino telescopes certainly stand out. Neutrinos telescopes, made of large volume of a transparent medium observed by optical sensors, can detect high energy neutrinos from galactic or extra-galactic sources, and they can also be used for the study of neutrino properties. ANTARES and its successor KM3NeT are two neutrino telescopes located in the Mediterranean sea. ANTARES operations started in 2007 and it has taken data almost continuously until the beginning of 2022. KM3NeT, taking advantage from the experience of ANTARES, aims to be the most sensitive neutrino telescope in the next generation of detectors. This thesis presents my contributions to both detectors. In particular, the technical part of the work has been developed in collaboration with KM3NeT. It is devoted to the the study of data from the compasses installed in the KM3NeT detection elements: from their calibration before deployment to the analysis of their data in the sea. These compasses allow a tracking of the movements of the detector elements in the sea. In collaboration with ANTARES a physics analysis related to the search of dark matter annihilation in the Sun has been developed analyzing thirteen years of data. New upper limits for neutrino and antineutrino fluxes from dark matter annihilation in the Sun have been obtained, and from these upper limits on the Dark Matter - Nucleon scattering cross section have been obtained. These results improve previous ANTARES results by a factor of 2 and are competitive with those obtained by other experiments. / Poirè, C. (2022). Dark Matter Searches Towards the Sun with ANTARES and Positioning Studies for KM3NeT [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/188750

<p>A search for a diffuse flux of cosmic neutrinos with energies in excess of 10¹⁴ eV was performed using two years of AMANDA-II data, collected in 2003 and 2004. A 20% evenly distributed sub-sample of experimental data was used to verify the detector description and the analysis cuts. A very good agreement between this 20% sample and the background simulations was observed. The analysis was optimised for discovery, to a relatively low price in limit setting power. The background estimate for the livetime of the examined 80% sample is 0.035 ± 68% events with an additional 41% systematical uncertainty.</p><p>The total neutrino flux needed for a 5σ discovery to be made with 50% probability was estimated to 3.4 ∙ 10^-7 <i>E</i>^-2 GeV s^-1 sr^-1 cm^-2 equally distributed over the three flavours, taking statistical and systematic uncertainties in the background expectation and the signal efficiency into account. No experimental events survived the final discriminator cut. Hence, no ultra-high energy neutrino candidates were found in the examined sample. A 90% upper limit is placed on the total ultra-high energy neutrino flux at 2.8 ∙ 10^-7 <i>E</i>^-2 GeV s^-1 sr^-1cm^-2, taking both systematical and statistical uncertainties into account. The energy range in which 90% of the simulated <i>E</i>^-2signal is contained is 2.94 ∙ 10¹⁴ eV to 1.54 ∙ 10¹⁸eV (central interval), assuming an equal distribution over the neutrino flavours at the Earth. The final acceptance is distributed as 48% electron neutrinos, 27% muon neutrinos, and 25% tau neutrinos.</p><p>A set of models for the production of neutrinos in active galactic nuclei that predict spectra deviating from <i>E</i>^-2 was excluded.</p>

No description available.

In this doctoral thesis, we study both low- and high-energy observables related to massive neutrinos. Neutrino oscillations have provided indisputable evidence in favour of non-zero neutrino masses and mixings. However, the original formulation of the Standard Model cannot account for these observations, which calls for the introduction of new Physics. Among many possibilities, we focus here on the inverse seesaw, a neutrino mass generation mechanism in which the Standard Model is extended with fermionic gauge singlets. This model offers an attractive alternative to the usual seesaw realisations since it can potentially have natural Yukawa couplings (O(1)) while keeping the new Physics scale at energies within reach of the LHC. Among the many possible effects, this scenario can lead to deviations from lepton flavour universality. We have investigated these signatures and found that the ratios R_K and R_π provide new, additional constraints on the inverse seesaw. We have also considered the embedding of the inverse seesaw in supersymmetric models. This leads to increased rates for various lepton flavour violating processes, due to enhanced contributions from penguin diagrams mediated by the Higgs and Z bosons. Finally, we also found that the new invisible decay channels associated with the sterile neutrinos present in the supersymmetric inverse seesaw could significantly weaken the constraints on the mass and couplings of a light CP-odd Higgs boson.

The lack of direct evidence for physics beyond the SM at the LHC has led some to reevaluate the need for such physics to solve the hierarchy problem. Instead, the notion that the SM, or something like it, is valid up to the Planck scale and that technical naturalness is sufficient for solving the hierarchy problem has been suggested. This thesis examines minimal extensions of the SM that address its phenomenological and theoretical shortcomings while avoiding new physics between the electroweak and Planck scales that introduces a hierarchy problem. This thesis first studies two issues with the vMSM - an extension of the SM by three right-handed neutrinos - and their possible solutions. The first issue is the tension between dark matter production in the nuMSM and constraints from the Lyman-alpha forest data. To avoid this tension, the vMSM is extended by a Higgs singlet &Phi; and neutrino dark matter is produced through the decays of &Phi; rather than through left-right neutrino mixing. It is shown that the hierarchical parameters of this model can arise from symmetries broken at or near the Planck scale for two specific examples: one in which &Phi; stabilizes the electroweak vacuum and one in which &Phi; is a light inflaton. The second issue pertains to Higgs &xi;-inflation. In the vMSM, a large non-minimal coupling &xi; of the Higgs to gravity gives inflation but leads to a possible violation of perturbative unitarity below the inflationary scale. A study of Higgs &xi;-inflation with M_h &simeq; 125-126 GeV, for which the Higgs self-coupling &lambda; runs to small values near the Planck scale, is carried out. It is shown that small &lambda; can significantly reduce &xi; required for inflation, but &xi; cannot be small enough to address the possible unitarity issue. For small &lambda;, a new region of Higgs &xi;-inflation with a large tensor-to-scalar ratio r that is consistent with BICEP2 is discovered. This thesis then studies the technical naturalness and cosmology of a model that addresses the strong CP problem. It is shown that a classically scale invariant DFSZ invisible a&xi;on model with a Peccei-Quinn scalar S, whose couplings to the SM are ultra-weak, can solve the strong CP problem and generate electroweak symmetry breaking via the Coleman-Weinberg mechanism. The ultra-weak couplings of S are natural due to an underlying appro&xi;mate shift symmetry. The model contains a light pseudo-Goldstone dilaton that can be consistent with cosmological bounds while the a&xi;on can be the dark matter of the universe. Finally, a summary of the thesis is presented and future research topics are suggested.

Há várias evidências experimentais da existência de matéria escura no universo. Apesar destas evidências, pouco se sabe sobre sua constituição, sabendo-se apenas que interage gravitacionalmente, mas não eletromagneticamente. Neste projeto, investigamos a possibilidade da matéria escura ser composta por partículas supermassivas e fortemente interagentes (Simpzillas). Para isto determinamos o sinal que deve ser deixado no telescópio IceCube por neutrinos resultantes de aniquilações de matéria escura no Sol. Após determinarmos o espectro de neutrinos no centro do Sol, simulamos sua propagação até a superfície, depois até a Terra e através da Terra até o detector. Comparamos então estes resultados com os fornecidos pelo IceCube. Esta comparação permite testar uma região do espaço de fase massa versus seção de choque previamente não-excluída por outros tipos de experiência que não telescópios de neutrinos. Como resultado, concluímos que partículas supermassivas e fortemente interagentes não podem constituir a matéria escura. / There are many experimental evidences for the existence of dark matter in the universe. Despite these evidences, there is no knowledge about its constitution other than the fact that it interacts gravitationally but not electromagnetically. In this project, we investigate the possibility that dark matter is composed of strongly interacting massive particles (Simpzillas). We determine the expected signal in the IceCube telescope from Simpzilla annihilation in the center of the Sun. We first determine the neutrino spectrum in the core of the Sun. We then simulate its propagation through both the Sun and Earth, and finally the rate of neutrinos at the detector. A comparison of these results to the ones published by the IceCube collaboration covers a large region of the yet not excluded regions of the mass versus cross-section phase space. As a result, the possibility of Simpzillas composing the dark matter is ruled out.