Particles Physics
Mostrando 13-24 de 62 artigos, teses e dissertações.
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13. Estudo comparativo das respostas de monitores de Rn-222 que utilizam o CR-39 como detector de tracos de particulas alfa / Response comparative study os Rn-222 alpha particle track monitors
This work was a comparative study between the responses of three monitors, the NRPB, an acrylic monitor (in thin film geometry) and the aluminum monitor (also thin film geometry) in controled and mixed environment. The experiments consisted on placing the monitors in a plastic tube, with a radio-226 source internal. Only internal CR-39 plastic detectors were
Publicado em: 2010
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14. O vértice D*Dp usando as regras de soma da QCD / The D*Dp vertex using the QCD sum rules
The particle physics have been studying topics like the Quark-Gluon Plasma (QGP), Higgs boson and dark matter, which require experiments in heavy-ion collisions. Therefore, accelerators capable of generate high energy particle beams are necessary and may generate new physics. When new data arise in the laboratories, new processes are necessary to explain thi
Publicado em: 2010
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15. Study of the structure of new mesons / Estudo da estrutura dos novos mésons
We use QCD sum rules to test the nature of the recently observed mesons Y (4260), Y (4360) and Y (4660), assumed to be exotic four-quark (c¯cq¯q) or (c¯cs¯s) states with JPC = 1. We work at leading order in s, consider the contributions of higher dimension condensates and keep terms which are linear in the strange quark mass ms. We find for the (c¯cs¯s
Publicado em: 2009
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16. Aspectos dinâmicos de espalhamento caótico clássico / Dynamical aspects of classical scattering
In this thesis we study different scattering systems with chaos. Chaotic scattering, present in a large variety of physical systems, is a type of transient chaos. While the phase-space of such systems is unbounded, irregular motion occurs only in a bounded area, called the scattering region. Still, any (nontrivial) scattering function relating initial condit
Publicado em: 2009
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17. Processos estocásticos em física: teoria e fundamentos
This work discusses some problems in physics using the language of stochastic processes. Firstly, we discuss the relationships between the formalisms of master equations, path integrals, and jumping processes. Each of them is a different prescription to define a Markovian process. Using these formalisms, we discuss the applicability of the classic Langevin m
Publicado em: 2009
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18. Geometria, Topologia e Elasticidade: aplicações a membranas e outros sistemas bidimensionais
Geometry, topology and elasticity are found in various branchs of physics and they play important roles in the understanding of many physical phenomena. In this work, we present three diferent systems where we can see such importance. First, a quantum neutral particle, constrained to move on a conical surface, is used as a toy model to explore bound states d
Publicado em: 2009
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19. Análise da propagação de neutrinos na matéria e aplicações em geofísica
A oscilação entre sabores de neutrinos, fenômeno proposto para explicar discrepâncias no fluxo observado de neutrinos em vários contextos, é afetada pela matéria na qual o neutrino se propaga. Em geral, para simplificar o tratamento, a oscilação entre três sabores é aproximada para o contexto de duas famílias. Aqui, a solução exata para o opera
Publicado em: 2009
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20. Influence of vinasse application in saturated hydraulic conductivity and runoff / Influência da aplicação de vinhaça na condutividade hidráulica do solo saturado e no escoamento superficial
The production of alcohol used as fuel is increasing every year due to the need to replace the sources of fossil fuels, which is finite, and on the other hand alcohol is a renewable energy source. But the production of this fuel generates large quantities of waste and the vinasse draws most attention by its high value as fertilizer, primarily by the amount o
Publicado em: 2009
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21. Study of nuclear reactions of astrophysics interest through the trojan horse method / Estudo de reações nucleares de interesse astrofísico utilizando o método do cavalo de tróia
Nuclear Astrophysics is the key to explain, among other things, the production of energy in stars, stellar evolution and the synthesis of chemical elements and isotopes in the Universe. In such cases, nuclear reactions are the main structure, where cross sections and reaction rates must be determined with reasonable accuracy in the laboratory. Because the ex
Publicado em: 2009
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22. A unidade ontolÃgica do mundo em Werner Heisenberg
The main purpose of this dissertation is to analyze the philosophical and ontological assumptions about the monistic idea from the thinking of the german physicist Werner Heisenberg. They are remarkable efforts in the twentieth century to find a unified theory of matter or, to use the title of this dissertation, a ontological unity of the real. Throughout hi
Publicado em: 2008
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23. Matéria escura supersimétrica
A identidade da matéria escura é um dos grandes enigmas do nosso Universo. A solução para este mistério pode estar associada à supersimetria, uma simetria que relaciona férmions e bósons, ainda não verificada experimentalmente. Em muitas extensões supersimétricas do Modelo Padrão da física de partículas, a partícula supersimétrica mais leve (
Publicado em: 2008
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24. Computational animation of fluid flow using SPH / Animação computacional de escoamento de fluidos utilizando o método SPH
Since the late 70s, there is a growing interest in physically-based simulations due to its increasing range of application. Among these simulations, we may highlight interaction between rigid, elastic, plastic and breakable bodies and also fluids. In this work, one of these phenomena, fluid flow, is simulated using a technique known as Smoothed Particle Hydr
Publicado em: 2008