61,406 research outputs found

    Fisher matrix forecasts for astrophysical tests of the stability of the fine-structure constant

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    We use Fisher Matrix analysis techniques to forecast the cosmological impact of astrophysical tests of the stability of the fine-structure constant to be carried out by the forthcoming ESPRESSO spectrograph at the VLT (due for commissioning in late 2017), as well by the planned high-resolution spectrograph (currently in Phase A) for the European Extremely Large Telescope. Assuming a fiducial model without α\alpha variations, we show that ESPRESSO can improve current bounds on the E\"{o}tv\"{o}s parameter---which quantifies Weak Equivalence Principle violations---by up to two orders of magnitude, leading to stronger bounds than those expected from the ongoing tests with the MICROSCOPE satellite, while constraints from the E-ELT should be competitive with those of the proposed STEP satellite. Should an α\alpha variation be detected, these measurements will further constrain cosmological parameters, being particularly sensitive to the dynamics of dark energy.Comment: Phys. Lett. B (in press

    Propagação vegetativa de espécies silvestres de Manihot.

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    A mandioca (Manihot esculenta Crantz) tem sua importância na alimentação humana e animal, devido à sua capacidade de reserva de amido em suas raízes. No Brasil ocorrem cerca de 80% das espécies silvestres existentes no mundo, apresentando uma ampla variabilidade genética

    Investigation of the agricultural resources in Sri Lanka

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    The author has identified the following significant results. Several in-house capabilities were developed. The facilities to prepare color composites of excellent quality were developed, using bulk B/W 70 mm transparencies or 1:1,000,000 positive transparencies. These color composites were studied through optical devices on light tables. A zoom transfer scope was also added, enabling direct transfer of LANDSAT composite data on to base maps

    Alternativas de insumos para manejo em sistemas agrícolas de base ecológica.

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    bitstream/CNPS-2009-09/14003/1/circtec40_2008alternativa_insumos.pd

    A Simple Realization of the Inverse Seesaw Mechanism

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    Differently from the canonical seesaw mechanism, which is grounded in grand unified theories, the inverse seesaw mechanism lacks a special framework that realizes it naturally. In this work we advocate that the 3-3-1 model with right-handed neutrinos has such an appropriate framework to accommodate the inverse seesaw mechanism. We also provide an explanation for the smallness of the μ\mu parameter and estimate the branching ratio for the rare lepton flavor violation process μeγ\mu \rightarrow e\gamma.Comment: About 14pages, no figures, basis corrected, to appear at the PR

    Combining type I and type II seesaw mechanisms in the minimal 3-3-1 model

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    The minimal 3-3-1 model is perturbative until energies around 4-5TeV, posing a challenge to generate neutrino masses at eV scale, mainly if one aims to take advantage of the seesaw mechanism. As a means to circumvent this problem we propose a modification of the model such that it accommodates the type I and type II seesaw mechanisms altogether. We show that the conjunction of both mechanisms yield a neutrino mass expression suppressed by a high power of the cutoff scale, M5M^5, in its denominator. With such a suppression term we naturally obtain neutrino masses at eV scale when MM is around few TeV. We also investigate the size of lepton flavor violation through the process μeγ\mu \rightarrow e\gamma.Comment: about 15 pages, no figure
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