6,479 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

    Get PDF
    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

    Neutrino cross-section measurement with neutrinos from muon decay

    Full text link
    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

    Search for charginos, neutralinos, and gravitinos at LEP

    Get PDF
    The hep-ex data base was decided not to be an appropriate place to make DELPHI notes public. Sorry for the inconvenience.Comment: the paper should not have been made publi

    Morpho-Anatomical Characterisation of the Rhizomes of Ten Species of Curcuma L. (Zingiberaceae) from south India

    Get PDF
    The morphological and anatomical characterisation of ten medicinally and economically important species of Curcuma L. from South India namely, C. aeruginosa (neela-kua), C. amada (manga-inchi), C. aromatica (kasturi-manjal), C. aurantiaca, C. caesia (kari-manjal), C. haritha (karpura-kua), C. longa (manjal), C. montana, C. zanthorrhiza (manja-kua) and C. zedoaria (chenthandan-kua) were studied and compared. Eventhough, all the species show similarity in their characters, striking differences were noticed with respect to morphological characters such as shape and size of mother rhizome and lateral branches, colour of the cut surface, aroma and taste of rhizomes etc. Differences were also observed in some anatomical characters such as nature of endodermoid layer, size and shape of starch grains, oil cells and curcumin cells, etc. Based on the distinct morpho-anatomical features, an artificial dichotomous key was proposed for taxonomic delimitation of the species with their rhizome
    corecore