187 research outputs found

    Long term performance of the MINOS calibration procedure and stability of the MINOS detectors

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    The MINOS detectors are steel-scintilla tor sampling tracking calorimeters and are calibrated using an in-situ light-injection system and cosmic ray muons. The MINOS Near and Far Detectors have been operating almost continuously since 2003 and 2005, providing opportunity to quantify the behavior of the various detector components, many of which are used in the next generation neutrino oscillation experiments, under long-term experimental operation. We report, oil the calibration procedure mid its stability, as well as the time aud temperature dependencies of the scintillator, wavelength-shifting fibers and photo-multiplier tubes

    Global neutrino data and recent reactor fluxes: status of three-flavour oscillation parameters

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    We present the results of a global neutrino oscillation data analysis within the three-flavour framework. We include latest results from the MINOS long-baseline experiment (including electron neutrino appearance as well as anti-neutrino data), updating all relevant solar (SK II+III), atmospheric (SK I+II+III) and reactor (KamLAND) data. Furthermore, we include a recent re-calculation of the anti-neutrino fluxes emitted from nuclear reactors. These results have important consequences for the analysis of reactor experiments and in particular for the status of the mixing angle θ13\theta_{13}. In our recommended default analysis we find from the global fit that the hint for non-zero θ13\theta_{13} remains weak, at 1.8σ\sigma for both neutrino mass hierarchy schemes. However, we discuss in detail the dependence of these results on assumptions concerning the reactor neutrino analysis.Comment: 15 pages, 10 figures and 2 tables, v2: corrected version, main conclusions unchanged, references adde

    Lepton flavor violation in SUSY left-right symmetric theories

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    The seesaw mechanism is the most popular explanation for the smallness of neutrino masses. However, its high scale makes direct tests impossible and only indirect signals at low energies are reachable for collider experiments. One of these indirect links with the high scale is lepton flavor violation (LFV). We discuss LFV decays of sleptons in the context of a SUSY left-right symmetric model that naturally incorporates the seesaw mechanism. This non-minimal embedding of the seesaw leads to observable LFV effects in the right-handed sleptons sector, contrary to minimal models where these are found to be totally negligible. Therefore, LFV observables can be used as a powerful tool to study physics right below the GUT scale.Comment: To appear in the proceedings of PASCOS 2010, the 16th International Symposium on Particles, Strings and Cosmology, Valencia, Spai

    Reactor Neutrino Experiments with a Large Liquid Scintillator Detector

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    We discuss several new ideas for reactor neutrino oscillation experiments with a Large Liquid Scintillator Detector. We consider two different scenarios for a measurement of the small mixing angle θ13\theta_{13} with a mobile νˉe\bar{\nu}_e source: a nuclear-powered ship, such as a submarine or an icebreaker, and a land-based scenario with a mobile reactor. The former setup can achieve a sensitivity to sin22θ130.003\sin^2 2\theta_{13} \lesssim 0.003 at the 90% confidence level, while the latter performs only slightly better than Double Chooz. Furthermore, we study the precision that can be achieved for the solar parameters, sin22θ12\sin^2 2\theta_{12} and Δm212\Delta m_{21}^2, with a mobile reactor and with a conventional power station. With the mobile reactor, a precision slightly better than from current global fit data is possible, while with a power reactor, the accuracy can be reduced to less than 1%. Such a precision is crucial for testing theoretical models, e.g. quark-lepton complementarity.Comment: 18 pages, 3 figures, 2 tables, revised version, to appear in JHEP, Fig. 1 extended, Formula added, minor changes, results unchange

    Neutrino Beams From Electron Capture at High Gamma

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    We investigate the potential of a flavor pure high gamma electron capture electron neutrino beam directed towards a large water cherenkov detector with 500 kt fiducial mass. The energy of the neutrinos is reconstructed by the position measurement within the detector and superb energy resolution capabilities could be achieved. We estimate the requirements for such a scenario to be competitive to a neutrino/anti-neutrino running at a neutrino factory with less accurate energy resolution. Although the requirements turn out to be extreme, in principle such a scenario could achieve as good abilities to resolve correlations and degeneracies in the search for sin^2(2 theta_13) and delta_CP as a standard neutrino factory experiment.Comment: 21 pages, 7 figures, revised version, to appear in JHEP, Fig.7 extended, minnor changes, results unchange

    Status of Neutrino Masses and Mixing and Future Perspectives

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    Status of the problem of neutrino masses, mixing and oscillations is discussed. Future perspectives are briefly considered.Comment: Report at the conference IRGAC 2006, Barcelona July 11-15 200

    Where we are on θ13\theta_{13}: addendum to "Global neutrino data and recent reactor fluxes: status of three-flavour oscillation parameters"

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    In this addendum to arXiv:1103.0734 we consider the recent results from long-baseline νμνe\nu_\mu\to\nu_e searches at the T2K and MINOS experiments and investigate their implications for the mixing angle θ13\theta_{13} and the leptonic Dirac CP phase δ\delta. By combining the 2.5σ2.5\sigma indication for a non-zero value of θ13\theta_{13} coming from T2K data with global neutrino oscillation data we obtain a significance for θ13>0\theta_{13} > 0 of about 3σ3\sigma with best fit points sin2θ13=0.013(0.016)\sin^2\theta_{13} = 0.013(0.016) for normal (inverted) neutrino mass ordering. These results depend somewhat on assumptions concerning the analysis of reactor neutrino data.Comment: 5 pages, 2 figures and 1 tabl

    A low energy optimization of the CERN-NGS neutrino beam for a theta_{13} driven neutrino oscillation search

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    The possibility to improve the CERN to Gran Sasso neutrino beam performances for theta_{13} searches is investigated. We show that by an appropriate optimization of the target and focusing optics of the present CNGS design, we can increase the flux of low energy neutrinos by about a factor 5 compared to the current tau optimized focalisation. With the ICARUS 2.35 kton detector at LNGS and in case of negative result, this would allow to improve the limit to sin^22 theta_{13} by an order of magnitude better than the current limit of CHOOZ at Delta m^2 approximately 3 times 10^{-3} eV^2 within 5 years of nominal CNGS running. This is by far the most sensitive setup of the currently approved long-baseline experiments and is competitive with the proposed JHF superbeam.Comment: 19 pages, 8 figure

    Public Health for the Internet φ Towards A New Grand Challenge for Information Management

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    Business incentives have brought us within a small factor of achieving the database community\u27s Grand Challenge set out in the Asilomar Report of 1998. This paper makes the case for a new, focused Grand Challenge: Public Health for the Internet. The goal of PHI (or φ) is to enable collectives of hosts on the Internet to jointly monitor and promote network health by sharing information on network conditions in a peer-to-peer fashion. We argue that this will be a positive effort for the research community for a variety of reasons, both in terms of its technical reach and its societal impact. This version of the φ vision is targeted at readers in the database research community, but the effort is clearly multidisciplinary. A more generalist version of this paper will be maintained at http://openphi.net
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