2,404 research outputs found

    Future neutrino oscillation facilities

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    The recent discovery that neutrinos have masses opens a wide new field of experimentation. Accelerator-made neutrinos are essential in this program. Ideas for future facilities include high intensity muon neutrino beams from pion decay (`SuperBeam'), electron neutrino beams from nuclei decays (`Beta Beam'), or muon and electron neutrino beams from muon decay (`Neutrino Factory'), each associated with one or several options for detector systems. Each option offers synergetic possibilities, e.g. some of the detectors can be used for proton decay searches, while the Neutrino Factory is a first step towards muon colliders. A summary of the perceived virtues and shortcomings of the various options, and a number of open questions are presented.Comment: Originally written for the CERN Strategy Grou

    The uncoupling limit of identical Hopf bifurcations with an application to perceptual bistability

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    We study the dynamics arising when two identical oscillators are coupled near a Hopf bifurcation where we assume a parameter ϵ\epsilon uncouples the system at ϵ=0\epsilon=0. Using a normal form for N=2N=2 identical systems undergoing Hopf bifurcation, we explore the dynamical properties. Matching the normal form coefficients to a coupled Wilson-Cowan oscillator network gives an understanding of different types of behaviour that arise in a model of perceptual bistability. Notably, we find bistability between in-phase and anti-phase solutions that demonstrates the feasibility for synchronisation to act as the mechanism by which periodic inputs can be segregated (rather than via strong inhibitory coupling, as in existing models). Using numerical continuation we confirm our theoretical analysis for small coupling strength and explore the bifurcation diagrams for large coupling strength, where the normal form approximation breaks down

    The Golden Channel at a Neutrino Factory revisited: improved sensitivities from a Magnetised Iron Neutrino Detector

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    This paper describes the performance and sensitivity to neutrino mixing parameters of a Magnetised Iron Neutrino Detector (MIND) at a Neutrino Factory with a neutrino beam created from the decay of 10 GeV muons. Specifically, it is concerned with the ability of such a detector to detect muons of the opposite sign to those stored (wrong-sign muons) while suppressing contamination of the signal from the interactions of other neutrino species in the beam. A new more realistic simulation and analysis, which improves the efficiency of this detector at low energies, has been developed using the GENIE neutrino event generator and the GEANT4 simulation toolkit. Low energy neutrino events down to 1 GeV were selected, while reducing backgrounds to the 10410^{-4} level. Signal efficiency plateaus of ~60% for νμ\nu_\mu and ~70% for νˉμ\bar{\nu}_\mu events were achieved starting at ~5 GeV. Contamination from the νμντ\nu_\mu\rightarrow \nu_\tau oscillation channel was studied for the first time and was found to be at the level between 1% and 4%. Full response matrices are supplied for all the signal and background channels from 1 GeV to 10 GeV. The sensitivity of an experiment involving a MIND detector of 100 ktonnes at 2000 km from the Neutrino Factory is calculated for the case of sin22θ13101\sin^2 2\theta_{13}\sim 10^{-1}. For this value of θ13\theta_{13}, the accuracy in the measurement of the CP violating phase is estimated to be ΔδCP35\Delta \delta_{CP}\sim 3^\circ - 5^\circ, depending on the value of δCP\delta_{CP}, the CP coverage at 5σ5\sigma is 85% and the mass hierarchy would be determined with better than 5σ5\sigma level for all values of δCP\delta_{CP}

    Distribution of Planorbulinacea (benthic foraminifera) assemblages in surface sediments on the northern margin of the Gulf of Cadiz

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    The distributional patterns and related environmental parameters for four species of benthic foraminifera of the Superfamily Planorbulinacea occurring in surface sediments from the northeast Gulf of Cadiz are discussed. Their distribution is related to bathymetry, in the case of Hyalinea balthica (Schröter, 1783), and to the texture of the sediments in the area for the other three, Cibicides refulgens (Montfort, 1808), Lobatula lobatula (Walter and Jacob, 1798) and Planorbulina mediterranensis (d´Orbigny 1826). Two characteristic assemblages were differentiated with Q-mode analysis: F1 (H. balthica), affected mainly by water depth; and F2 (C. refulgens and L. lobatula), related to the substrate, typical of high-energy/low sedimentation rate environments.Se ha determinado el área de distribución de las cuatro especies de foraminíferos bentónicos de la superfamilia Planorbulinacea encontrados en los sedimentos superficiales del margen septentrional del golfo de Cádiz. Su distribución está relacionada, en el caso de Hyalinea balthica (Schröter, 1783), con la batimetría, y las otras tres, Cibicides refulgens (Montfort 1808), Lobatula lobatula (Walter and Jacob, 1798) y Planorbulina mediterranensis (d'Orbigny, 1826) con las características texturales del sedimento. Hay dos asociaciones características: F1 (H. balthica) afectada principalmente por la profundidad en el dominio del agua noratlántica central y F2 (C. refulgens y L. lobatula) relacionada con el substrato, propia de ambientes de alta energía y baja tasa de sedimentación.Instituto Español de Oceanografí

    ROSLab Sharing ROS Code Interactively With Docker and JupyterLab

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    The success of the Robot Operating System (ROS) and the advance of open source ideas have radically changed and improved the experience of sharing software among members of the robotics community. Yet the lack of a suitable workflow for continuous integration and verification in robotics represents a significant obstacle to developing software that can be run by independent users for testing and reusing purposes

    Design and validation of a socio-emotional questionnaire for youth football players

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    Con el objetivo de detectar y controlar los factores socio-emocionales que influyen en la progresión del joven futbolista, se diseñó un cuestionario auto-cumplimentado de 40 ítems, agrupados en 3 dimensiones (entorno social, bienestar e inteligencia emocional). Se analizó la validez de contenido mediante la valoración de 14 expertos y la validez de constructo mediante análisis factorial. Se evaluó la fiabilidad del cuestionario, administrándolo a jóvenes futbolistas de élite (n=281) y analizando la consistencia interna por el método del Alfa de Cronbach y la fiabilidad test-retest mediante el coeficiente de correlación intraclase (CCI). El análisis factorial confirmó la existencia de 18 categorías, que en conjunto explican el 65,40% de la varianza total. El Alfa de Cronbach del cuestionario fue de 0,944 (p<0,01) y el CCI de 0,894 (p<0,01). El cuestionario reúne suficientes propiedades psicométricas como para ser considerado una herramienta válida y fiable para medir el entorno socio-emocional de jóvenes futbolistas.The objective of this study was to design a valid questionnaire to detect and manage the socio-emotional factors that influence the performance of young football players. A group of specialists designed a self-completion questionnaire of 40 items grouped into 3 dimensions. Content validity was analysed and evaluated by 14 experts and construct validity was analysed by factorial analysis. To evaluate reliability the questionnaire was administered to young elite football players, and internal consistency was analysed with Cronbach’s alpha. Test-retest reliability was assessed with the intraclass correlation coefficient (ICC). Factor analysis confirmed the existence of 18 factors, which as a whole explained 65.40% of the total variance. The Cronbach’s alpha of the questionnaire was 0.944 (p<0.01) and the ICC of the entire questionnaire was 0.894 (p<0.01). The questionnaire gathers together enough psychometric properties to be considered a valid and reliable tool for gauging the socio-emotional environment of young football players

    Summary of Golden Measurements at a ν\nu-Factory

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    The precision and discovery potential of a neutrino factory based on muon storage rings is summarized. For three-family neutrino oscillations, we analyze how to measure or severely constraint the angle θ13\theta_{13}, CP violation, MSW effects and the sign of the atmospheric mass difference Δm232\Delta m^2_{23}. The appearance of ``wrong-sign muons'' at three reference baselines is considered: 732 km, 3500 km and 7332 km. We exploit the dependence of the signal on the neutrino energy, and include as well realistic background estimations and detection efficiencies. The optimal baseline turns out to be OO(3000 km).Comment: 7 pages, Latex2e, 5 eps figures, use package espfi

    Neutrino Factories and the "Magic" Baseline

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    We show that for a neutrino factory baseline of L7300km7600kmL \sim 7300 km - 7 600 km a ``clean'' measurement of sin22θ13\sin^2 2 \theta_{13} becomes possible, which is almost unaffected by parameter degeneracies. We call this baseline "magic" baseline, because its length only depends on the matter density profile. For a complete analysis, we demonstrate that the combination of the magic baseline with a baseline of 3000 km is the ideal solution to perform equally well for the sin22θ13\sin^2 2 \theta_{13}, sign of Δm312\Delta m_{31}^2, and CP violation sensitivities. Especially, this combination can very successfully resolve parameter degeneracies even below sin22θ13<104\sin^2 2 \theta_{13} < 10^{-4}.Comment: Minor changes, final version to appear in PRD, 4 pages, 3 figures, RevTe

    Golden measurements at a neutrino factory

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    The precision and discovery potential of a neutrino factory based on muon storage rings is studied. For three-family neutrino oscillations, we analyse how to measure or severely constraint the angle θ13\theta_{13}, CP violation, MSW effects and the sign of the atmospheric mass difference Δm232\Delta m^2_{23}. We present a simple analytical formula for the oscillation probabilities in matter, with all neutrino mass differences non-vanishing, which clarifies the subtleties involved in disentangling the unknown parameters. The appearance of ``wrong-sign muons'' at three reference baselines is considered: 732 km, 3500 km, and 7332 km. We exploit the dependence of the signal on the neutrino energy, and include as well realistic background estimations and detection efficiencies. The optimal baseline turns out to be O(3000{\cal O}(3000 km). Analyses combining the information from different baselines are also presented.Comment: 45 pages, Latex2e, 24 figures using epsfig.sty. An incorrect statement and a few misprints have been corrected. Results and conclusions are unchange
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