14 research outputs found
Quasi-energy-independent solar neutrino transitions
Current solar, atmospheric, and reactor neutrino data still allow oscillation
scenarios where the squared mass differences are all close to 10^-3 eV^2,
rather than being hierarchically separated. For solar neutrinos, this situation
(realized in the upper part of the so-called large-mixing angle solution)
implies adiabatic transitions which depend weakly on the neutrino energy and on
the matter density, as well as on the ``atmospheric'' squared mass difference.
In such a regime of ``quasi-energy-independent'' (QEI) transitions,
intermediate between the more familiar ``Mikheyev-Smirnov-Wolfenstein'' (MSW)
and energy-independent (EI) regimes, we first perform analytical calculations
of the solar nu_e survival probability at first order in the matter density,
beyond the usual hierarchical approximations. We then provide accurate,
generalized expressions for the solar neutrino mixing angles in matter, which
reduce to those valid in the MSW, QEI and EI regimes in appropriate limits.
Finally, a representative QEI scenario is discussed in some detail.Comment: Title changed; text and acronyms revised; results unchanged. To
appear in PR
Time of arrival through interacting environments: Tunneling processes
We discuss the propagation of wave packets through interacting environments.
Such environments generally modify the dispersion relation or shape of the wave
function. To study such effects in detail, we define the distribution function
P_{X}(T), which describes the arrival time T of a packet at a detector located
at point X. We calculate P_{X}(T) for wave packets traveling through a
tunneling barrier and find that our results actually explain recent
experiments. We compare our results with Nelson's stochastic interpretation of
quantum mechanics and resolve a paradox previously apparent in Nelson's
viewpoint about the tunneling time.Comment: Latex 19 pages, 11 eps figures, title modified, comments and
references added, final versio
Collider aspects of flavour physics at high Q
This review presents flavour related issues in the production and decays of
heavy states at LHC, both from the experimental side and from the theoretical
side. We review top quark physics and discuss flavour aspects of several
extensions of the Standard Model, such as supersymmetry, little Higgs model or
models with extra dimensions. This includes discovery aspects as well as
measurement of several properties of these heavy states. We also present public
available computational tools related to this topic.Comment: Report of Working Group 1 of the CERN Workshop ``Flavour in the era
of the LHC'', Geneva, Switzerland, November 2005 -- March 200
Rendimento, composição e análise sensorial do queijo minas frescal fabricado com leite de vacas mestiças alimentadas com diferentes volumosos Yield, composition and sensory analysis of Minas cheese made with milk from crossbred cows fed different roughages
Objetivou-se com este trabalho avaliar a qualidade físico-química e sensorial e o perfil de ácidos graxos do queijo minas frescal produzido com o leite de vacas mestiças alimentadas com dietas contendo quatro volumosos: canade-açúcar, silagem de sorgo, silagem de girassol e pastagem de Panicum maximum cv. Tanzânia. Foram avaliados o rendimento, a composição físico-química e o perfil de ácidos graxos. Também foi realizada a análise sensorial do queijo minas frescal e da composição físico-química do leite. Utilizaram-se oito vacas mestiças 1/2 Holandês/Gir, com período de lactação de 180 ± 12 dias, distribuídas em dois quadrados latinos 4 × 4, com quatro animais, quatro dietas e quatro períodos. Os períodos foram de 18 dias, sendo 15 dias de adaptação e três dias de coletas de dados. Após o processamento do queijo, foi feita análise microbiológica, físico-química e posteriormente análise sensorial. Amostras do queijo foram congeladas e analisadas quanto ao perfil de ácidos graxos. O teor de gordura do queijo foi maior para as dietas com cana-de-açúcar e silagem de girassol em relação à silagem de sorgo e ao pasto de Panicum maximum cv. Tanzânia, que não diferiram entre si. O queijo produzido a partir do leite de vacas alimentadas com silagem de girassol apresentou melhor perfil de ácidos graxos e índices de qualidade nutricional, maior proporção e melhor perfil de ácidos graxos insaturados. O rendimento do queijo foi igual para todas as dietas, independentemente do volumoso utilizado em sua composição. O queijo produzido com o leite de vacas alimentadas com silagem de girassol tem maior preferência pelos julgadores no teste de análise sensorial, especialmente quanto ao atributo aparência.<br>The objective of this study was to evaluate the physical-chemical and sensory quality and fatty acid profile of Minas cheese produced from milk from crossbred cows fed diets with four roughages (sugar cane, sorghum silage, sunflower silage and pasture of Panicum maximum cv. Tanzania). Yield, physical-chemical composition, fatty acid profile and sensory analysis of Minas cheese, as well as the physical-chemical composition of milk were analyzed. For the experiment, eight 1/2 Holstein/Gir crossbred cows, with lactation period of 180 ± 12 days were distributed in two 4 × 4 latin squares (four animals, four diets and four periods). The experimental periods had a duration of 18 days: 15 days of adaptation and three days of data collection. After cheese processing microbiological, physical-chemical and sensory analysis were done. Cheese samples were frozen and analyzed for fatty acid profile. The fat content of cheese was higher for diets with sugar cane and sunflower silage compared with sorghum silage and pasture of Panicum maximum cv. Tanzania. Cheese produced from milk from cows fed sunflower silage had superior fatty acid composition and nutritional quality indexes, and better profile and higher proportion of unsaturated fatty acids. Cheese yield did not differ between diets containing different roughages. Cheese produced from milk from cows fed a diet with sunflower silage presents higher preference at the sensory analysis test, especially regarding the attribute appearance