4,733 research outputs found

    The Muon Anomalous Magnetic Moment in the Reduced Minimal 3-3-1 Model

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    We study the muon anomalous magnetic moment (g2)μ(g-2)_{\mu} in the context of the reduced minimal 3-3-1 model recently proposed in the literature. In particular, its spectrum contains a doubly charged scalar (H±±H^{\pm \pm}) and gauge boson (U±±U^{\pm \pm}), new singly charged vectors (V±V^{\pm}) and a ZZ^{\prime} boson, each of which might give a sizeable contribution to the (g2)μ(g-2)_{\mu}. We compute the 1-loop contributions from all these new particles to the (g2)μ(g-2)_{\mu}. We conclude that the doubly charged vector boson provides the dominant contribution, and by comparing our results with the experimental constraints we derive an expected value for the scale of SU(3)LU(1)NSU(3)_L\otimes U(1)_N symmetry breaking vχ2v_{\chi} \sim 2 TeV. We also note that, if the discrepancy in the anomalous moment is resolved in the future without this model then the constraints will tighten to requiring vχ>2.7v_\chi > 2.7 TeV with current precision, and will entirely rule out the model if the expected precision is achieved by the future experiment at Fermilab.Comment: 19 pages, 4 figure

    The MIPSGAL View of Supernova Remnants in the Galactic Plane

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    We report the detection of Galactic supernova remnants (SNRs) in the mid-infrared (at 24 and 70 μm), in the coordinate ranges 10° < l < 65° and 285° < l < 350°, |b| < 1°, using MIPS aboard the Spitzer Space Telescope. We search for infrared counterparts to SNRs in Green's catalog and identify 39 out of 121, i.e., a detection rate of about 32%. Such a relatively low detection fraction is mainly due to confusion with nearby foreground/background sources and diffuse emission. The SNRs in our sample show a linear trend in [F_8/F_(24)] versus [F_(70)/F_(24)]. We compare their infrared fluxes with their corresponding radio flux at 1.4 GHz and find that most remnants have a ratio of 70 μm to 1.4 GHz which is similar to those found in previous studies of SNRs (with the exception of a few that have ratios closer to those of H II regions). Furthermore, we retrieve a slope close to unity when correlating infrared (24 and 70 μm) with 1.4 GHz emission. Our survey is more successful in detecting remnants with bright X-ray emission, which we find is well correlated with the 24 μm morphology. Moreover, by comparing the power emitted in the X-ray, infrared, and radio, we conclude that the energy released in the infrared is comparable to the cooling in the X-ray range

    Suppression of Anderson localization of light and Brewster anomalies in disordered superlattices containing a dispersive metamaterial

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    Light propagation through 1D disordered structures composed of alternating layers, with random thicknesses, of air and a dispersive metamaterial is theoretically investigated. Both normal and oblique incidences are considered. By means of numerical simulations and an analytical theory, we have established that Anderson localization of light may be suppressed: (i) in the long wavelength limit, for a finite angle of incidence which depends on the parameters of the dispersive metamaterial; (ii) for isolated frequencies and for specific angles of incidence, corresponding to Brewster anomalies in both positive- and negative-refraction regimes of the dispersive metamaterial. These results suggest that Anderson localization of light could be explored to control and tune light propagation in disordered metamaterials.Comment: 4 two-column pages, 3 figure

    As variedades crioulas de cebola e o potencial de uso em sistemas agroecologicos.

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    Objetivou-se descrever os sistemas de cultivo de cebola tradicionais e avaliar o potencial dos genótipos crioulos para sistemas agroecológicos

    Reference gene selection for gene expression studies in apple.

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    Apple (Malus x domestica Borkh.) is the most important deciduous tree fruit crop grown around the world, and also in the Southern of Brazil. Researches on apple genetic breeding include disease resistance mechanisms, grafting, chilling requirement, fruit ripening and production of nutraceutical compounds.Resumo

    Reference genes for transcriptional analysis of flowering and fruit ripening stages in apple (Malus 3 domestica Borkh.).

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    Apple (Malus 9 domestica Borkh.) is the most important deciduous tree fruit crop grown around the world. Comparisons of gene expression profiles from different tissues, conditions or cultivars are valuable scientific tools to better understand the gene expression changes behind important silvicultural and nutritional traits. However, the accuracy of techniques employed to access gene expression is dependent on the evaluation of stable reference genes for data normalization to avoid statistical significance undue or incorrect conclusions. The objective of this work was to select the best genes to be used as references for gene expression studies in apple trees by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Vegetative and reproductive tissues of the apple ??Gala?? cultivar were evaluated during their seasonal cycle of growth and dormancy. The expression of 23 traditional housekeeping genes or genes suggested as constitutive by microarray data was investigated. Tested combinations of primers allowed the specific amplification and the generation of suitable efficiency curves for gene expression studies by RT-qPCR. Gene stability was determined by two different statistical descriptors, geNorm and Norm-Finder. The known variable PAL gene expression was used to validate selected normalizers. Results obtained allowed us to conclude that MDH, SAND, THFS, TMp1 and WD40 are the best reference genes to accurately normalize the relative transcript abundances using RT-qPCR in various tissues of apple.DOI 10.1007/s11032-014-0078-
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