20,533 research outputs found

    R2D2 - a symmetric measurement of reactor neutrinos free of systematical errors

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    We discuss a symmetric setup for a reactor neutrino oscillation experiment consisting of two reactors separated by about 1 km, and two symmetrically placed detectors, one close to each reactor. We show that such a configuration allows a determination of sin22θ13\sin^22\theta_{13} which is essentially free of systematical errors, if it is possible to separate the contributions of the two reactors in each detector sufficiently. This can be achieved either by considering data when in an alternating way only one reactor is running or by directional sensitivity obtained from the neutron displacement in the detector.Comment: 11 pages, 3 figures, clarifications added, some numbers in relation with the neutron displacement corrected, version to appear in JHE

    Physics Potential of a 2540 Km Baseline Superbeam Experiment

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    We study the physics potential of a neutrino superbeam experiment with a 2540 km baseline. We assume a neutrino beam similar to the NuMI beam in medium energy configuration. We consider a 100 kton totally active scintillator detector at a 7 mr off-axis location. We find that such a configuration has outstanding hierarchy discriminating capability. In conjunction with the data from the present reactor neutrino experiments, it can determine the neutrino mass hierarchy at 3 sigma level in less than 5 years, if sin^2(2*theta13) > 0.01, running in the neutrino mode alone. As a stand alone experiment, with a 5 year neutrino run and a 5 year anti-neutrino run, it can determine non-zero theta13 at 3 sigma level if sin^2(2*theta13) > 7*10^{-3} and hierarchy at 3 sigma level if sin^2(2*theta13) > 8*10^{-3}. This data can also distinguish deltaCP = pi/2 from the CP conserving values of 0 and pi, for sin^2(2*theta13) > 0.02.Comment: 16 pages, 7 figures and 1 table: Published versio

    Resolving Octant Degeneracy at LBL experiment by combining Daya Bay Reactor Setup

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    Long baseline Experiment (LBL) have promised to be a very powerful experimental set up to study various issues related to Neutrinos. Some ongoing and planned LBL and medium baseline experiments are - T2K, MINOS, NOvA, LBNE, LBNO etc. But the long baseline experiments are crippled due to presence of some parameter degeneracies, like the Octant degeneracy. In this work, we first show the presence of Octant degeneracy in LBL experiments, and then combine it with Daya Bay Reactor experiment, at different values of CP violation phase. We show that the Octant degeneracy in LBNE can be resolved completely with this proposal.Comment: 4 pages, 8 figure

    Regional and labour market development in candidate countries: a literature survey

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    There has been substantial convergence of candidate countries to Western European institutions and labour market outcomes. Despite this, the labour markets in the candidate countries have their individual features: long and persistent reductions in employment rates as well as a higher incidence of long-term unemployment; more severe mass redundancy regulations and weaker trade unions and social partnership organisations; low turnover in and out of unemployment; and declining internal migration. Accession will trigger institutional changes by the social acquis, environmental and competition policy as well as – at a later stage – accession to EMU, the impact of the EU's structural policy on the candidate countries, and changes in trade, foreign direct investment and migration. In assessing the consequences of these changes, literature is far from unanimous, but some hypotheses can be developed: 1. Integration will have important structural and distributional effects and positive aggregate effects. 2. The capability of labour markets to adjust to such shocks will determine the labour market outcomes of integration. 3. Extrapolating purely from the current labour market dynamics to a time after enlargement may lead to misinterpretations, since "adjustment mechanisms" are endogenous. 4. National policy decisions and use of structural funds are a key in triggering regional convergence. Regional issues should be given attention when analysing integration effects. Experience from previous enlargements suggests that convergence is far from automatic after accession. Policy takes a decisive role in determining the outcomes. Regional development in candidate countries suggests some potential for further divergence

    CP, T and CPT violation in future long baseline experiments

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    I give a short overview about the possibilities and problems related to the measurement of CP violation in long baseline experiments. Special attention is paid to the issue of degeneracies and a method for their resolution is quantitatively discussed. The CP violation reach for different experiments is compared in dependence of sin22θ13\sin^22\theta_{13} and \dm{21}. Furthermore a short comment about the possible effects of matter induced T violation is made. Finally the limits on CPT violation obtainable at a neutrino factory are shown.Comment: Talk presented at NUFACT02, London, 1-6 July, 2002. 3 pages, 2 figure

    Ritalin and ADHD: recent developments

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    Superconducting atomic contacts under microwave irradiation

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    We have measured the effect of microwave irradiation on the dc current-voltage characteristics of superconducting atomic contacts. The interaction of the external field with the ac supercurrents leads to replicas of the supercurrent peak, the well known Shapiro resonances. The observation of supplementary fractional resonances for contacts containing highly transmitting conduction channels reveals their non-sinusoidal current-phase relation. The resonances sit on a background current which is itself deeply modified, as a result of photon assisted multiple Andreev reflections. The results provide firm support for the full quantum theory of transport between two superconductors based on the concept of Andreev bound states

    Untangling CP Violation and the Mass Hierarchy in Long Baseline Experiments

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    In the overlap region, for the normal and inverted hierarchies, of the neutrino-antineutrino bi-probability space for νμνe\nu_\mu \to \nu_e appearance, we derive a simple identity between the solutions in the (sin22θ13\sin^2 2\theta_{13}, sinδ\sin \delta) plane for the different hierarchies. The parameter sin22θ13\sin^2 2\theta_{13} sets the scale of the νμνe\nu_\mu \to \nu_e appearance probabilities at the atmospheric δmatm22.4×103\delta m^2_{atm} \approx 2.4 \times 10^{-3} eV2^2 whereas sinδ\sin \delta controls the amount of CP violation in the lepton sector. The identity between the solutions is that the difference in the values of sinδ\sin \delta for the two hierarchies equals twice the value of sin22θ13\sqrt{\sin^2 2\theta_{13}} divided by the {\it critical} value of sin22θ13\sqrt{\sin^2 2\theta_{13}}. We apply this identity to the two proposed long baseline experiments, T2K and NOν\nuA, and we show how it can be used to provide a simple understanding of when and why fake solutions are excluded when two or more experiments are combined. The identity demonstrates the true complimentarity of T2K and NOν\nuA.Comment: 15 pages, Latex, 4 postscript figures. Submitted to New Journal of Physics, ``Focus on Neutrino Physics'' issu

    Topologically non-trivial quantum layers

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    Given a complete non-compact surface embedded in R^3, we consider the Dirichlet Laplacian in a layer of constant width about the surface. Using an intrinsic approach to the layer geometry, we generalise the spectral results of an original paper by Duclos et al. to the situation when the surface does not possess poles. This enables us to consider topologically more complicated layers and state new spectral results. In particular, we are interested in layers built over surfaces with handles or several cylindrically symmetric ends. We also discuss more general regions obtained by compact deformations of certain layers.Comment: 15 pages, 6 figure
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