<p>This thesis is devoted to the study of neutrino physics in general and the study of neutrino mixing and oscillations in particular. In the standard model of particle physics, neutrinos are massless, and as a result, they do not mix or oscillate. However, many experimental results now seem to give evidence for neutrino oscillations, and thus, the standard model has to be extended in order to incorporate neutrino masses and mixing among different neutrino flavors.</p><p>When neutrinos propagate through matter, the neutrino mixing, and thus, also the neutrino oscillations, may be significantly altered. While the matter effects may be easily studied in a framework with only two neutrino flavors and constant matter density, we know that there exists (at least) three neutrino flavors and that the matter density of the Universe is far from constant. This thesis includes studies of three-flavor effects and a solution to the two-flavor neutrino oscillation problem in matter with an arbitrary density profile.</p><p>Furthermore, there have historically been attempts to describe the neutrino flavor transitions by other effects than neutrino oscillations. Even if these effects now seem to be disfavored as the leading mechanism, they may still give small corrections to the neutrino oscillation formulas. These effects may lead to erroneous determination of the fundamental neutrino oscillation parameters and are also studied in this thesis in form of damping factors.</p>

Artificial infiltration has been increasing in popularity in Sweden as a way to combat over-abstraction of groundwater aquifers from growing municipalities. However, enteric virus contamination of drinking water sources is a concern as infiltrating surficial waters are easily contaminated from human activities. Therefore, it is imperative that effective drinking water treatment is maintained to prevent infection throughout the municipalities. Furthermore, a better quantification of environmental parameters affect-ing virus mobility could significantly improve infiltration schemes for virus removal purposes. In this study, the removal efficiency of MS2 bacteriophage was investigated in relation to dissolved organic matter and ionic strength on new and used sand from the Tunåsen infiltration basin in Uppsala, Sweden. Virus removal was measured by static batch equilibrium experiments and first order decay models were used as interpretative models. Soil associated organic matter displayed the greatest effect on virus removal between all parameters. The highest removal efficiency was seen in samples containing low soil associated organic matter. Similarly, an inverse relationship with dissolved organic matter and virus removal rate was determined. Samples without soil showed the opposite relationship between dis-solved organic matter and virus removal. A higher decrease in MS2 phage was observed with higher dissolved organic matter in soil-negative samples. The removal kinetics of MS2 with higher ionic strength had a closer correlation with the linear time-invariant removal model, whereas samples with low ionic strength had a closer relation with the nonlinear time-dependent removal model. However, ionic strength was shown to have very little effect on overall virus removal efficiency. Fastest and slowest viral removal rates were modeled in the HYDRUS 1D program to determine the amount of potential contamination of the water table beneath the Uppsala Esker. The degree of contamination at the bottom of the infiltration basins was also determined. The sample with the highest rate of virus removal displayed an 11.77% greater decrease in phage concentration at the water table than samples with the lowest rate of removal. However the approximation of maximum contamination was deemed unrealistic due to the assumption that the entire esker was made of sand. On the other hand, the sample with the highest rate of removal showed only a 0.60% greater decrease in phage concentration following the infiltration basin. This study therefore suggests that a more frequent replacement of quartz sand in infiltration basins has little value in overall drinking water quality. / I Sverige har så kallad konstgjord infiltrering, det vill säga perkolation av ytvatten ned i grundvattensystem, blivit ett allt vanligare tillvägagångssätt för att tillmötesgå den ökande efterfrågan av färskt dricksvatten bland Sveriges växande kommuner. Tyvärr är föroreningar av virus i dricksvatten ett vanligt bekymmer eftersom ytvatten enkelt förorenas genom mänskliga aktiviteter, vilket bland annat har observerats genom en ökning av diarréfall under vintermånaderna. Därför är det viktigt att en bra vattenbehandling upprätthålls för att förebygga fler insjuknanden hos befolkningen.Tidigare studier visar att ökning av organiskt material bidrar till förhöjd transport av virus i konstgjorda infiltreringsprojekt. Detta eftersom organiskt material binder till jordpartiklar och därför tar upp den plats som viruset annars skulle bundit till. Istället för att viruset binder till jorden och tas bort från vattnet, stannar det kvar och transporteras vidare i grundvattensystemet och kan då nå den vattentäkt där dricksvatten tas till samhället. Ökad förekomst av organiskt material skulle alltså kunna öka risken att kommunalt dricksvatten förorenas av virus.I denna studie användes prover tagna från det område i Uppsala där ytvatten infiltreras i marken för att genomgå naturlig rening. Proverna undersöktes för att se hur mycket virus som tas bort under den naturliga rengöringsprocessen. Borttagningen av virus mättes i en så kallad ”static batch equilibrium experiments”, vilket innebär att mängden virus i vattnet uppskattas utifrån tre olika parametrar, mätt över tid. De testade parametrarna är mängd organisk materia löst i vattnet, lösningens jonstyrka och mängd organisk materia bunden till jorden. För att jämföra de olika parametrarna och för att bestämma hur snabbt virus tas bort från vattnet, användes olika linjära modeller.Resultaten visade att organiskt material bundet till jord var den parameter som hade störst effekt på virusborttagning, där låg halt organiskt material är bunden till jord avlägsnades mest virus. Halten organisk materia löst i vatten har en liknande trend där en hög halt inte avlägsnar så mycket virus, medan en låg halt däremot avlägsnar mer virus. Proverna utan jord visade motsatt effekt mellan löst organisk materia och virusborttagning, det vill säga mer virus avlägsnades ju mer organisk materia som var löst i vattnet. Jonstyrkan hade ingen signifikant effekt på virusborttagningen.Två olika scenarion, värsta och bästa tänkbara, modellerades i programmet HYDRUS 1D för att kunna bestämma inom vilket intervall en eventuell förorening i Uppsalaåsens grundvatten skulle kunna ligga. Även graden av förorening längst ner i infiltreringsbassängen, bestående av ett metertjockt lager sand som placerats ovanpå Uppsalaåsen för att bidra till reningsprocessen, modellerades och bestämdes för att bättre kunna förutse när byte av sand är lämpligast.Provet som visade högst virusborttagning, det vill säga det bästa tänkbara scenariot, var 11.77 % effektivare än provet med långsammast virusborttagning. Däremot bestämdes det att uppskattningen av maximal förorening var orealistisk eftersom det i modellen antogs att hela åsen bestod av sand, medan åsar i själva verket består av många andra fraktioner och jordarter utöver sand, till exempel grus och sten.Provet med snabbast virusborttagning hade bara 0.60 % större minskning i koncentration av virus efter att vattnet passerat infiltreringsbassängen, än provet med lägst virusborttagning. Denna studie föreslår därför att det är av litet värde att byta ut sanden i infiltrationsbassängen då denna procedur har liten påverkan på dricksvattenkvalitén generellt.

This thesis is devoted to the study of neutrino physics in general and the study of neutrino mixing and oscillations in particular. In the standard model of particle physics, neutrinos are massless, and as a result, they do not mix or oscillate. However, many experimental results now seem to give evidence for neutrino oscillations, and thus, the standard model has to be extended in order to incorporate neutrino masses and mixing among different neutrino flavors. When neutrinos propagate through matter, the neutrino mixing, and thus, also the neutrino oscillations, may be significantly altered. While the matter effects may be easily studied in a framework with only two neutrino flavors and constant matter density, we know that there exists (at least) three neutrino flavors and that the matter density of the Universe is far from constant. This thesis includes studies of three-flavor effects and a solution to the two-flavor neutrino oscillation problem in matter with an arbitrary density profile. Furthermore, there have historically been attempts to describe the neutrino flavor transitions by other effects than neutrino oscillations. Even if these effects now seem to be disfavored as the leading mechanism, they may still give small corrections to the neutrino oscillation formulas. These effects may lead to erroneous determination of the fundamental neutrino oscillation parameters and are also studied in this thesis in form of damping factors. / QC 20101124

Nesta tese, realizamos dois tipos de estudos fenomenológicos através de uma análise detalhada de alguns experimentos terrestres atuais e futuros. No primeiro, estudamos dois mecanismos exóticos de conversão de sabor: descoerência quântica e interações não padrão do neutrino com a matéria. Para descoerência, vinculamos o parâmetro de descoerência bem como testamos como distinguir a solução de descoerência pura do mecanismo padrão de oscilação no contexto de duas gerações. No caso das interações não padrão, assumimos que esta é subdominante frente ao mecanismo de oscilação padrão, e encontramos os possíveis limites que poderão ser obtidos para essas interações utilizando uma fábrica de neutrinos futura. No segundo tipo de estudo, determinamos os parâmetros de oscilação solares pela análise combinada dos dados dos neutrinos solares e de KamLAND, e estimamos a precisão nos parâmetros de mistura atmosféricos que poderá ser atingida pelos experimentos de LongBaseLine futuros MINOS, ICARUS e OPERA. Por fim, investigamos a possibilidade dos experimentos futuros do duplo decaimento sem neutrinos de determinar os parâmetros de não oscilação. / In this thesis, we have done two kind of phenomenological studies through a detailed analysis of present and future terrestrial experiments. In the first study, we analyze two exotic mechanisms of flavour conversion: quantum decoherence and non-standard neutrino-matter interactions. In the case of decoherence, we impose constraints on the decoherence parameter and test how to distinguish between the pure decoherence solution and the standard neutrino ascillation mechanism in the contexto f two neutrino generations. For non-standard interactions, assuming it as a sub-leading process compared to the standard oscillation, we find the possible limits that can be achieved on the strength of these interactions using a future neutrino factory. In the second part of the study, we determine the solar oscillation parameters using a combined analysis of solar neutrino and KamLAND data, and estimate the precision on the atmospheric mixing parameters by that can be accomplished by the LongBaseline experiments MINOS, ICARUS and OPERA. Finally, we investigate the capability of future neutrinoless Double beta decay experiments to determine the non-oscillation parameters.

This thesis is devoted to the theory and phenomenology of neutrino physics. While the standard model of particle physics has been extremely successful, it fails to account for massive neutrinos, which are necessary to describe the observations of neutrino oscillations made by several different experiments. Thus, neutrino physics is a possible window for exploring the physics beyond the standard model, making it both interesting and important for our fundamental understanding of Nature. Throughout this thesis, we will discuss different aspects of neutrino physics, ranging from taking all three types of neutrinos into account in neutrino oscillation experiments to exploring the possibilities of neutrino mass models to produce a viable source of the baryon asymmetry of the Universe. The emphasis of the thesis is on neutrino oscillations which, given their implication of neutrino masses, is a phenomenon where other results that are not describable in the standard model could be found, such as new interactions between neutrinos and fermions. / QC 20100630

Nesta tese, realizamos dois tipos de estudos fenomenológicos através de uma análise detalhada de alguns experimentos terrestres atuais e futuros. No primeiro, estudamos dois mecanismos exóticos de conversão de sabor: descoerência quântica e interações não padrão do neutrino com a matéria. Para descoerência, vinculamos o parâmetro de descoerência bem como testamos como distinguir a solução de descoerência pura do mecanismo padrão de oscilação no contexto de duas gerações. No caso das interações não padrão, assumimos que esta é subdominante frente ao mecanismo de oscilação padrão, e encontramos os possíveis limites que poderão ser obtidos para essas interações utilizando uma fábrica de neutrinos futura. No segundo tipo de estudo, determinamos os parâmetros de oscilação solares pela análise combinada dos dados dos neutrinos solares e de KamLAND, e estimamos a precisão nos parâmetros de mistura atmosféricos que poderá ser atingida pelos experimentos de LongBaseLine futuros MINOS, ICARUS e OPERA. Por fim, investigamos a possibilidade dos experimentos futuros do duplo decaimento sem neutrinos de determinar os parâmetros de não oscilação. / In this thesis, we have done two kind of phenomenological studies through a detailed analysis of present and future terrestrial experiments. In the first study, we analyze two exotic mechanisms of flavour conversion: quantum decoherence and non-standard neutrino-matter interactions. In the case of decoherence, we impose constraints on the decoherence parameter and test how to distinguish between the pure decoherence solution and the standard neutrino ascillation mechanism in the contexto f two neutrino generations. For non-standard interactions, assuming it as a sub-leading process compared to the standard oscillation, we find the possible limits that can be achieved on the strength of these interactions using a future neutrino factory. In the second part of the study, we determine the solar oscillation parameters using a combined analysis of solar neutrino and KamLAND data, and estimate the precision on the atmospheric mixing parameters by that can be accomplished by the LongBaseline experiments MINOS, ICARUS and OPERA. Finally, we investigate the capability of future neutrinoless Double beta decay experiments to determine the non-oscillation parameters.

[pt] Nesta tese estudamos o potencial que terão a próxima geração de detectores de neutrinos (JUNO, Hyper-Kamiokande e DUNE) para a detecção dos efeitos da matéria da Terra através da identificação das modulações no espectro de energia dos neutrinos de supernovas de colapso de núcleo em nossa galáxia, assumindo a possibilidade do decaimiento invisível de v2 após os neutrinos terem deixado a estrela, caminho da Terra. Simulações recentes do colapso gravitacional (e subsequente explosão) de estrelas com massa maior do que ~ 8Mo mostram que durante a fase de esfriamento as energias médias (Eve) e (Evx) tornam-se muito semelhantes e os fluxos tendem a se igualar, tornando difícil observar os efeitos da matéria da Terra usando um único detector. Neste trabalho mostramos que a inclusão do decaimiento dos neutrinos também cria a possibilidade de observar os efeitos em consideração no canal de detecção de neutrinos se o ordenamento de massa for normal e no canal anti-neutrino se o ordenamento for invertido, o que não é esperado na ausência de decaimento. Em particular, se a taxa de decaimento for maior do que ~ 70%, descobrimos que o decaimento invisível de v2 pode aumentar as possibilidades de observação dos efeitos da matéria da Terra, mesmo para supernovas a uma distância de 10 kpc de nós. / [en] In this thesis we studied the potential that the next-generation neutrino detectors (JUNO, Hyper-Kamiokande and DUNE) will have to the detection of the Earth matter effects through the identification of the modulations in the energy spectrum of neutrinos from core-collapse supernovae in our galaxy, assuming the possibility of the invisible decay of v2 after the neutrinos have left the star, on their way to Earth. Recent simulations of gravitational collapse (and subsequent explosion) of stars more massive than ~ 8Mo show that during the cooling phase the average energies (EVe) and (Evx) become very similar and the fluxes tend to equalize, making it difficult to observe the Earth matter effects using a single detector. In this work we show that the inclusion of neutrino decay creates also the possibility of observing the effects under consideration in the neutrino detection channel if the mass ordering is normal and in the anti-neutrino channel if the ordering is inverted, which is not expected in the absence of neutrino decay. In particular, if the decay rate is more than ~ 70%, we find that the invisible neutrino decay of v2 can enhance the observation possibilities of Earth matter effects even for supernovae at a distance of 10 kpc from us.