Neutrino Oscillation
Mostrando 1-12 de 16 artigos, teses e dissertações.
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1. Fenomenologia dos decaimentos de neutrinos de supernova / Decay phenomenology of supernova neutrinos
Here we present a study of the phenomenology of neutrinos, which starts with a model beyond the Standard Model, which generates mass and decay to neutrinos. The model was proposed by Gelmini and Roncadelli cite Gelmini: 1981, the model needs a triplet that interacts with the scaling doublet Higgs through different potential climb. The triplet also interacts
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 17/11/2011
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2. Development of formalism for neutrino evolution in the early universe / Desenvolvimento de formalismo para evolução de neutrinos no universo primordial
In this work, we studied some aspects of neutrino physics, using the state vector and density matrix formalisms, with the goal of understanding the neutrino evolution in the primordial universe. In the rst approach, we analysed the phenomenum of neutrino oscillation in vacuum, the induced matter potential and its expression as a refraction index, and the inf
Publicado em: 2009
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3. Neutrinos from supernovae / Neutrinos de supernovas
Com este trabalho buscamos entender o fenômeno de oscilações de neutrinos na matéria. Para isto, estudamos a propagação de neutrinos em Supernovas. O estudo é feito nestes objetos astrofísicos, pois são produzidos neutrinos de todos os sabores quando a estrela progenitor da Supernova é muito massiva. Além de isto, estes corpos celestes atingem den
Publicado em: 2008
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4. Wave packet description of neutrino oscillation in a progenitor star supernova environment
In this work we briefly review the wave packet approach of two generation neutrino oscillation, aiming its description in a progenitor star supernova environment. We begin calculating the wave packet size in many situations: solar and supernova plasma medium, considering nuclear interactions, as well as accelerators and reactors. This quantity is important t
Brazilian Journal of Physics. Publicado em: 2007-12
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5. Effects of solar neutrinos scale on atmospheric neutrino flux
In this work we try to understand the phenomena of neutrino oscillations, and use this to obtain a more precise description of the atmospheric neutrino data. The two neutrino oscillation mechanism solves the problem of the up-down muon neutrino asymmetry successfully. Our main motivation is to describe the excess of events of electron-neutrino type found in
Brazilian Journal of Physics. Publicado em: 2007-07
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6. Constraints on the environment depence of the neutrino mass from solar and reactor neutrino data
We investigate what can be the role of Mass Varying Neutrinos in several different neutrino oscillation experiments, in particular focusing on the relation between KamLAND data and solar neutrino experiment results. Assuming that the adiabaticity of solar neutrinos evolution in LMA-MSW scenario is not broken by the inclusion of this new mechanism, we can est
Brazilian Journal of Physics. Publicado em: 2007-07
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7. Estudo analítico das probabilidades de oscilação de neutrinos na matéria em três gerações / Analytical study of the neutrino iscillation probalities in the matter in three generations
Neste projeto realizamos um estudo sobre as fórmulas de probabilidades de oscilação de neutrinos na matéria em duas e três gerações. Estudamos extensivamente a fenomenologia e os experimentos de oscilação de neutrinos. Além de rever todas as expressões analíticas para as soluções exatas e aproximadas conhecidas na literatura para as probabilida
Publicado em: 2007
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8. Angra dos Reis reactor neutrino oscillation experiment
We present the status and plans of the Angra Project, a new reactor neutrino oscillation experiment, proposed to be built in Brazil at the Angra dos Reis nuclear complex. This experiment is aimed to measure theta13, the last unknown of the three neutrino mixing angles. We propose a high sensitivity multi-detector experiment, able to reach a sensitivity to an
Brazilian Journal of Physics. Publicado em: 2006-12
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9. Oscilação de neutrinos no formalismo de pacotes de onda / Neutrino oscillation in the wave packet approach
Generally, we study neutrino oscillation phenomenon using the plane wave formalism, which successfully treats the solar neutrino case, the reactor and accelerator cases. However, a more complete description of neutrino oscillation must consider a wave packet approach. This work analyses both formalisms: the plane wave and the wave packet in vacuum and matter
Publicado em: 2006
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10. Spin flavor oscillation of neutrinos in rotating gravitational fields and their effects on pulsar kicks
The origin of high velocities of pulsars is studied by considering the spin-flip conversion of neutrinos propagating in a gravitational field of a protoneutron star. For a rotating gravitational source (such as pulsars) with angular velocity , one finds that the spin connections (entering in the Dirac equation written in curved space time) induce an addition
Brazilian Journal of Physics. Publicado em: 2005-06
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11. Dark energy in the universe, the irreversibility of time and neutrinos
In this review, I discuss briefly how the presence of a cosmological constant in the Universe may imply a decoherent evolution of quantum matter in it, and as a consequence a fundamental irreversibility of time unrelated in principle to CP properties (Cosmological CPT Violation). In this context, I also discuss recently suggested novel possible contributions
Brazilian Journal of Physics. Publicado em: 2005-06
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12. KamLAND data and the solution to the solar neutrino problem
The first KamLAND results are in a very good agreement with the predictions made on the basis of the solar neutrino data and the LMA realization of the MSW mechanism. We perform a combined analysis of the KamLAND (rate, spectrum) and the solar neutrino data with a free boron neutrino flux fB. The best fit values of neutrino parameters are deltam² = 7.1.10-5
Brazilian Journal of Physics. Publicado em: 2004-12