7,104 research outputs found

    On the energy and baseline optimization to study effects related to the δ-phase (CP-/T-violation) in neutrino oscillations at a neutrino factory

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    In this paper we discuss the detection of CP- and T-violation effects in the framework of a neutrino factory. We introduce three quantities, which are good discriminants for a non-vanishing complex phase (δ) in the 3 × 3 neutrino mixing matrix: Δδ, ΔCP and ΔT. We find that these three discriminants (in vacuum) all scale with L/Ev, where L is the baseline and Ev the neutrino energy. Matter effects modify the scaling, but these effects are large enough to spoil the sensitivity only for baselines larger than 5000 km. So, in the hypothesis of constant neutrino factory power (i.e., number of muons inversely proportional to muon energy), the sensitivity on the δ-phase is independent of the baseline chosen. Specially interesting is the direct measurement of T-violation from the "wrong-sign" electron channel (i.e., the ΔT discriminant), which involves a comparison of the ve → vμ and vμ → ve oscillation rates. However, the vμ → ve measurement requires magnetic discrimination of the electron charge, experimentally very challenging in a neutrino detector. Since the direction of the electron curvature has to be estimated before the start of the electromagnetic shower, low-energy neutrino beams and hence short baselines, are preferred. In this paper we show, as an example, the exclusion regions in the Δm212-δ plane using the ΔCP and ΔT discriminants for two concrete cases keeping the same L/Ev ratio (730 km/7.5 GeV and 2900 km/30 GeV). We obtain a similar excluded region provided that the electron detection efficiency is ∼20% and the charge confusion 0.1%. The Δm212 compatible with the LMA solar data can be tested with a flux of 5 × 1021 muons. We compare these results with the fit of the visible energy distributions. © 2002 Elsevier Science B.V. All rights reserved

    Métodos de quimiluminiscencia (presente y futuro)

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    This article provides a general review of chemiluminescent methods in some of their recent applications in drug analysis, sea water analysis or antioxidant activity of natural and synthetic products (including olive oil). Practical considerations are not included in the review since the main interest is to state, through the aforementioned applications, that chemiluminescence has been, is, and will be a versatile tool for Analytical Chemistry in future years.Este artículo da una visión general de los métodos de quimiluminiscencia en algunas de las aplicaciones más recientes en análisis de drogas, análisis del agua marina o la actividad antioxidante de productos naturales y de síntesis (incluyendo el aceite de oliva). Las consideraciones prácticas no están incluidas ya que el principal interés es establecer, a través de las aplicaciones mencionadas, que la quimiluminiscencia ha sido, es y será en los próximos años una herramienta versátil de la Química Analítica

    Титульна сторінка та зміст

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    Neutrino cross-section measurement with neutrinos from muon decay

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    In this paper we stress the idea that new, more precise neutrino cross-sections measurements at low energies will be necessary to improve the results of future big neutrino detectors, which will be dominated by the contribution of the systematic errors. The use of a muon beam instead of the traditional pion beams is proposed. This choice allows the simultaneous measurement of both, numu and nue interactions and the two helicities, in a clean environment and with a precise knowledge of the beam flux. We show that with approx 10^{15} mu's/year and a moderate mass detector (approx 100 tons) placed close to the muon storage ring, precisions of the order of 10% in sigma(nu) (E_nu bin size of 100 MeV) can be reached for neutrino energies below 2 GeV.Comment: 4 pages, proceeding to NUFACT0

    Growth hormone AluI polymorphism analysis in eight Portuguese bovine breeds

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    A total of 195 bulls of eight Portuguese beef cattle breeds (Alentejana, Arouquesa, Barros , Maronesa, Marinhoa, Mertolenga, Mirandesa and Preta) were genotyped for the GH AluI polymorphism by the polymerase chain reaction and restriction length polymorphism (PCRRFLP). The genotype and gene frequencies for each breed were determined and shown to be quite variable among the breeds. The overall gene frequencies for L and V were 0.759 and 0.241, respectively. The relation between the bGH-AluI polymorphism and growth performances was ascertained in 168 of the animals analysed. According to our results there is a significant association between the genotypes LL and LV of the bGH and the average live body weight of the animals of the breeds Alentejana, Marinhoa and Preta

    Territory quality and male dominance in Tropidurus torquatus (Squamata, Tropiduridae)

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    In territorial species, females are often attracted by high-quality territories, which are expected to be owned by males that successfully won competition with other males. Because morphological and behavioral traits frequently influence males' combat success, these parameters may be used by females to assess the male (and associated territory) quality. In the present study, we tested the hypothesis that organismal traits in dominant males of the lizard Tropidurus torquatus are associated with the quality of the territory owned. After characterizing the territories occupied, we used a discriminant analysis to test if morphological and behavioral traits of the dominant male predict the quality of the territory owned. High-quality territories were characterized by a larger number of refuges, shorter distances among shelters and a well-defined harem, in comparison with low-quality territories. Organismal traits predicted with 100% accuracy the type of the territory owned: high-quality territories were associated with larger males that had longer heads, while males occupying low-quality territories exhibited more head displays, traveled larger distances and ran slightly slower than those associated with high-quality territories. We discuss possible implications of territory quality and male traits for reproductive success in Tropidurus torquatus

    Territory quality and male dominance in Tropidurus torquatus (Squamata, Tropiduridae)

    Get PDF
    In territorial species, females are often attracted by high-qualityterritories, which are expected to be owned by males that successfully won competition with other males. Because morphological and behavioral traits frequently influence males’ combat success, these parameters may be used by females to assess the male (and associated territory) quality. In the present study, we tested the hypothesis that organismal traits in dominant males of the lizard Tropidurus torquatus are associated with the quality of the territory owned. After characterizing the territories occupied, we used a discriminant analysis to test if morphological and behavioral traits of the dominant male predict the quality of the territory owned. High-quality territories were characterized by a larger number of refuges, shorter distances among shelters and a well-defined harem, in comparison with low-quality territories. Organismal traits predicted with 100% accuracy the type of the territory owned: high-quality territories were associated with larger males that had longer heads, while males occupying lowquality territories exhibited more head displays, traveled larger distances and ran slightly slower than those associated with high-quality territories. We discuss possibleimplications of territory quality and male traits for reproductive success in Tropidurus torquatus
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