214 research outputs found

    First results from dark matter search experiment with LiF bolometer at Kamioka Underground Laboratory

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    Tokyo group has performed first underground dark matter search experiment in 2001 through 2002 at Kamioka Observatory(2700m.w.e). The detector is eight LiF bolometers with total mass 168g aiming for the direct detection of WIMPs via spin-dependent interaction. With a total exposure of 4.1 kg days, we derived the limits in the a_p-a_n (WIMP-nucleon couplings) plane and excluded a large part of the parameter space allowed by the UKDMC experiment.Comment: 15 pages, 5 figure

    Limits on the WIMP-Nucleon Coupling Coefficients from Dark Matter Search Experiment with NaF Bolometer

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    We have performed the underground dark matter search experiment with a sodium fl uoride (NaF) bolometer array from 2002 through 2003 at Kamioka Observatory (2700 m.w.e.). The bolometer array consists of eight NaF absorbers with a total mass of 176 g, and sensitive NTD germanium thermistors glued to each of them. This experiment aims for the direct detection of weakly interacting massive part icles (WIMPs) via spin-dependent interaction. With an exposure of 3.38 kg days, we derived the limits on the WIMP-n ucleon coupling coefficients, a_p and a_n. These limits confirmed and tightened those derived from our previous results wit h the lithium fluoride (LiF) bolometer. Our results excluded the parameter space complementary to the results obtained b y NaI detectors of UKDMC experiment.Comment: 10 pages, 4 figure

    First report of Colletotrichum theobromicola and C. tropicale causing Anthracnose on fruits of Carnauba palm in Brazil.

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    Made available in DSpace on 2018-07-12T01:03:52Z (GMT). No. of bitstreams: 1 ART18036.pdf: 288445 bytes, checksum: 0d5022966fb2c0ea9bb92b9d8774ef8c (MD5) Previous issue date: 2018-07-09bitstream/item/179596/1/ART18036.pd

    First report of Lasiodiplodia brasiliense causing postharvest fruit rot of Custard Apple (Annona squamosa) in Brazil.

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    Made available in DSpace on 2018-07-12T01:03:41Z (GMT). No. of bitstreams: 1 ART18038.pdf: 298918 bytes, checksum: 119259227882f2be45395ab20d9be69b (MD5) Previous issue date: 2018-07-09bitstream/item/179595/1/ART18038.pd

    Anotações de doenças em espécies arbóreas no estado do Ceará.

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    A Embrapa Agroindústria Tropical implantou um campo de observação com diferentes espécies de árvores madeireiras nativas e exóticas no Município de Acaraú, na região compreendida pelo Distrito de Irrigação do Perímetro Baixo Acaraú, de maneira a acompanhar e observar o desenvolvimento dessas plantas em relação à adaptação das diferentes espécies.bitstream/item/174194/1/DOC18002.pd

    MEG Upgrade Proposal

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    We propose the continuation of the MEG experiment to search for the charged lepton flavour violating decay (cLFV) \mu \to e \gamma, based on an upgrade of the experiment, which aims for a sensitivity enhancement of one order of magnitude compared to the final MEG result, down to the 6×10146 \times 10^{-14} level. The key features of this new MEG upgrade are an increased rate capability of all detectors to enable running at the intensity frontier and improved energy, angular and timing resolutions, for both the positron and photon arms of the detector. On the positron-side a new low-mass, single volume, high granularity tracker is envisaged, in combination with a new highly segmented, fast timing counter array, to track positron from a thinner stopping target. The photon-arm, with the largest liquid xenon (LXe) detector in the world, totalling 900 l, will also be improved by increasing the granularity at the incident face, by replacing the current photomultiplier tubes (PMTs) with a larger number of smaller photosensors and optimizing the photosensor layout also on the lateral faces. A new DAQ scheme involving the implementation of a new combined readout board capable of integrating the diverse functions of digitization, trigger capability and splitter functionality into one condensed unit, is also under development. We describe here the status of the MEG experiment, the scientific merits of the upgrade and the experimental methods we plan to use.Comment: A. M. Baldini and T. Mori Spokespersons. Research proposal submitted to the Paul Scherrer Institute Research Committee for Particle Physics at the Ring Cyclotron. 131 Page

    Influência das épocas de floração e dos períodos de proteção fenológica à infecção do oídio no clone de cajueiro-anão BRS 189.

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    Made available in DSpace on 2018-01-18T22:14:50Z (GMT). No. of bitstreams: 1 ART17076.pdf: 154908 bytes, checksum: 4ac1589dd9389c98cb969c4e4e4a37a7 (MD5) Previous issue date: 2018-01-15bitstream/item/171363/1/ART17076.pd

    Measurement of the radiative decay of polarized muons in the MEG experiment

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    We studied the radiative muon decay μ+e+ννˉγ\mu^+ \to e^+\nu\bar{\nu}\gamma by using for the first time an almost fully polarized muon source. We identified a large sample (~13000) of these decays in a total sample of 1.8x10^14 positive muon decays collected in the MEG experiment in the years 2009--2010 and measured the branching ratio B(μ+e+ννˉγ\mu^+ \to e^+\nu\bar{\nu}\gamma) = (6.03+-0.14(stat.)+-0.53(sys.))x10^-8 for E_e > 45 MeV and E_{\gamma} > 40 MeV, consistent with the Standard Model prediction. The precise measurement of this decay mode provides a basic tool for the timing calibration, a normalization channel, and a strong quality check of the complete MEG experiment in the search for μ+e+γ\mu^+ \to e^+\gamma process.Comment: 8 pages, 7 figures. Added an introduction to NLO calculation which was recently calculated. Published versio

    Absorption of Scintillation Light in a 100 \ell Liquid Xenonγ\gamma Ray Detector and Expected Detector Performance

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    An 800L liquid xenon scintillation γ\gamma ray detector is being developed for the MEG experiment which will search for μ+e+γ\mu^+\to\mathrm{e}^+\gamma decay at the Paul Scherrer Institut. Absorption of scintillation light of xenon by impurities might possibly limit the performance of such a detector. We used a 100L prototype with an active volume of 372x372x496 mm3^3 to study the scintillation light absorption. We have developed a method to evaluate the light absorption, separately from elastic scattering of light, by measuring cosmic rays and α\alpha sources. By using a suitable purification technique, an absorption length longer than 100 cm has been achieved. The effects of the light absorption on the energy resolution are estimated by Monte Carlo simulation.Comment: 18 pages, 10 figures (eps). Submitted to Nucl. Instr. and Meth.
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