1,958 research outputs found

    νμ\nu_\mu disappearance at the SPL, T2K-I and the Neutrino Factory

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    We study the νμ\nu_\mu disappearance channel at T2K-phase I and the SPL and analyse the achievable reduction of present uncertainties in θ23\theta_{23} and Δm232\Delta m^2_{23}. We analyse the impact of discrete ambiguities in sign(Δm223\Delta m^2{23}) and sign(2tanθ232 \tan \theta_{23}). We show how the disappearance channel at the Neutrino Factory is complementary to the ``golden'' and ``silver'' appearance channels and can be used to reduce the eightfold-ambiguity problem in (θ13δ\theta_{13}-\delta).Comment: 2 pages, 3 epsfig; NUFACT'05, 21-26 June 2005, Frascat

    O papel das redes nacionais de pesquisa e educação nas ciências sociais

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    En este artículo se revisa el impacto de la transformación digital en las investigación en ciencias sociales. La posibilidad de usar grandes volúmenes de datos está limitada por la disponibilidad de infraestructura. En este contexto el rol de las redes nacionales de investigación y educación es fundamental. A tal fin se debe contar con un conjunto de servicios básicos expuestos a lo largo del texto y, finalmente, se proponen algunas acciones concretas para fortalecer la capacidad de los investigadores de usar esta tecnología para potenciar la capacidad de producir conocimiento y enfrentar los acuciantes problemas que enfrenta la humanidad

    Optimal β\beta-beam at the CERN-SPS

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    A β\beta-beam with maximum γ=150\gamma=150 (for \helio ions) or γ=250\gamma=250 (for \neon) could be achieved at the CERN-SPS. We study the sensitivity to θ13\theta_{13} and δ\delta of such a beam as function of γ\gamma, optimizing with the baseline constrained to CERN-Frejus (130 km), and also with simultaneous variation of the baseline. These results are compared to the {\it standard} scenario previously considered, with lower γ=60/100\gamma=60/100, and also with a higher γ350\gamma\sim 350 option that requires a more powerful accelerator. Although higher γ\gamma is better, loss of sensitivity to θ13\theta _{13} and δ\delta is most pronounced for γ\gamma below 100.Comment: 22 page

    A Fuzzy k-Nearest Neighbors Classifier to Deal with Imperfect Data

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    © 2018. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/ This document is the Accepted version of a Published Work that appeared in final form in Soft Computing. To access the final edited and published work see https://doi.org/10.1007/s00500-017-2567-xThe k-nearest neighbors method (kNN) is a nonparametric, instance-based method used for regression and classification. To classify a new instance, the kNN method computes its k nearest neighbors and generates a class value from them. Usually, this method requires that the information available in the datasets be precise and accurate, except for the existence of missing values. However, data imperfection is inevitable when dealing with real-world scenarios. In this paper, we present the kNNimp classifier, a k-nearest neighbors method to perform classification from datasets with imperfect value. The importance of each neighbor in the output decision is based on relative distance and its degree of imperfection. Furthermore, by using external parameters, the classifier enables us to define the maximum allowed imperfection, and to decide if the final output could be derived solely from the greatest weight class (the best class) or from the best class and a weighted combination of the closest classes to the best one. To test the proposed method, we performed several experiments with both synthetic and realworld datasets with imperfect data. The results, validated through statistical tests, show that the kNNimp classifier is robust when working with imperfect data and maintains a good performance when compared with other methods in the literature, applied to datasets with or without imperfection

    Shooting strategies and effectiveness after offensive rebound and its impact on game result in Euroleague basketball teams

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    Offensive rebound dominance has been widely shown as a key factor to success in basketball, since provide an extra attack. However, knowledge on how these second-options may results more effective is scarce. Thus, we aimed to discover the influence of shooting after offensive rebound on effectiveness, comparing differences between winners and losers. The sample consisted of 3010 shot attempts from Euroleague-Top-16. Variables pertaining to shooting effectiveness, shooting zone, and game result were registered through systematic observation. Statistical analyses included series of binomial logistic regression analyses. Results showed that shooting effectiveness increases by 67% when shooting after offensive rebound (OR= 1.67; p< 0.01). Additionally, winning teams were more effective after offensive rebound compared to losers (OR= 1.43; p= 0.03). Particularly, winners significantly scored more from the outside than defeated (OR= 3.40; p< 0.01), not finding differences in the inside (p= 0.62). In general, findings point out important advantages of shooting after offensive rebound, showing differences between winners and losers tactics. Thus, it is suggested developing specific tactical behaviours after offensive rebound situations to increase scoring opportunities and winning chances.

    Primary and secondary scintillation measurements in a xenon Gas Proportional Scintillation Counter

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    NEXT is a new experiment to search for neutrinoless double beta decay using a 100 kg radio-pure high-pressure gaseous xenon TPC. The detector requires excellent energy resolution, which can be achieved in a Xe TPC with electroluminescence readout. Hamamatsu R8520-06SEL photomultipliers are good candidates for the scintillation readout. The performance of this photomultiplier, used as VUV photosensor in a gas proportional scintillation counter, was investigated. Initial results for the detection of primary and secondary scintillation produced as a result of the interaction of 5.9 keV X-rays in gaseous xenon, at room temperature and at pressures up to 3 bar, are presented. An energy resolution of 8.0% was obtained for secondary scintillation produced by 5.9 keV X-rays. No significant variation of the primary scintillation was observed for different pressures (1, 2 and 3 bar) and for electric fields up to 0.8 V cm-1 torr-1 in the drift region, demonstrating negligible recombination luminescence. A primary scintillation yield of 81 \pm 7 photons was obtained for 5.9 keV X-rays, corresponding to a mean energy of 72 \pm 6 eV to produce a primary scintillation photon in xenon.Comment: 16 pages, 10 figures, accepted for publication in JINS

    Admixture of quasi-Dirac and Majorana neutrinos with tri-bimaximal mixing

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    We propose a realization of the so-called bimodal/schizophrenic model proposed recently. We assume S4, the permutation group of four objects as flavor symmetry giving tri-bimaximal lepton mixing at leading order. In these models the second massive neutrino state is assumed quasi-Dirac and the remaining neutrinos are Majorana states. In the case of inverse mass hierarchy, the lower bound on the neutrinoless double beta decay parameter m_ee is about two times that of the usual lower bound, within the range of sensitivity of the next generation of experiments.Comment: 8 pages, minor changes to match version accepted in PL
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