4,992 research outputs found

    Electric dipole and magnetic quadrupole moments of the WW boson via a CP-violating HWWHWW vertex in effective Lagrangians

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    The possibility of nonnegligible WW electric dipole (μ~W\widetilde{\mu}_W) and magnetic quadrupole (Q~W\widetilde{Q}_W) moments induced by the most general HWWHWW vertex is examined via the effective Lagrangian technique. It is assumed that new heavy fermions induce an anomalous CP-odd component of the HWWHWW vertex, which can be parametrized by an SUL(2)×UY(1)SU_L(2)\times U_Y(1)-invariant dimension-six operator. This anomalous contribution, when combined with the standard model CP-even contribution, lead to CP-odd electromagnetic properties of the WW boson, which are characterized by the form factors Δκ~\Delta \widetilde{\kappa} and ΔQ~\Delta \widetilde{Q}. It is found that Δκ~\Delta \widetilde{\kappa} is divergent, whereas ΔQ~\Delta \widetilde{Q} is finite, which reflects the fact that the latter cannot be generated at the one-loop level in any renormalizable theory. Assuming reasonable values for the unknown parameters, we found that μ~W36×1021\widetilde{\mu}_W\sim 3-6\times 10^{-21} e-cm, which is eight orders of magnitude larger than the SM prediction and close to the upper bound derived from the neutron electric dipole moment. The estimated size of the somewhat less-studied Q~W\widetilde{Q}_W moment is of the order of 1036-10^{-36} e-cm^2, which is fifteen orders of magnitude above the SM contribution.Comment: 7 pages, 6 figures, REVTEX styl

    CP-odd static electromagnetic properties of the W gauge boson and the t quark via the anomalous tbW coupling

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    In the framework of the electroweak chiral Lagrangian, the one-loop induced effects of the anomalous tbWtbW coupling, which includes both left- and right-handed complex components, on the static electromagnetic properties of the WW boson and the tt quark are studied. The attention is focused mainly on the CP-violating electromagnetic properties. It is found that the tbWtbW anomalous coupling can induce both CP-violating moments of the WW boson, namely, its electric dipole (μ~W\tilde{\mu}_W) and magnetic quadrupole (Q~W\tilde{Q}_W) moments. As far as the tt quark is concerned, a potentially large electric dipole moment (dt)(d_t) can arise due to the anomalous tbWtbW coupling. The most recent bounds on the left- and right-handed parameters from BB meson physics lead to the following estimates μ~W 10231022\tilde{\mu}_W ~ 10^{-23}-10^{-22} e-cm and Q~W 10381037\tilde{Q}_W~ 10^{-38}-10^{-37} e-cm2^2, which are 7 and 14 orders of magnitude larger than the standard model (SM) predictions, whereas dtd_t may be as large as 102210^{-22} e-cm, which is about 8 orders of magnitude larger than its SM counterpart.Comment: This paper has been merged with hep-ph/0612171 for publication in Physical Review

    Identificação de demandas para a cultura do coqueiro.

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    Capacidade de rebrota e de enraizamento de Eucalyptus benthamii.

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    A capacidade de rebrota e de enraizamento de estacas de Eucalyptus benthamii Maid e Camb. foram determinadas em um povoamento de sete anos de idade, estabelecido na Embrapa Florestas, em Colombo, PR. O corte das árvores, rente ao solo, foi efetuado em duas épocas do ano, primavera e outono. A partir das brotações oriundas das cepas, foram confeccionadas estacas. As estacas consistiram de segmentos de brotações de cerca de 15 cm de comprimento, contendo, um par de folhas com área foliar reduzida à metade, as quais foram, primeiramente, tratadas com fungicida e, posteriormente, com o ácido indol-3-butírico a 6000 ppm. A capacidade de rebrota foi de 87,3% e a maior capacidade de enraizamento foi na primavera, com 31,2%, comparada com 26,3% no outono

    Tunneling effects on impurity spectral function in coupled asymmetric quantum wires

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    The impurity spectral function is studied in coupled double quantum wires at finite temperatures. Simple anisotropy in the confinement direction of the wires leads to finite non-diagonal elements of the impurity spectral function matrix. These non-diagonal elements are responsible for tunneling effects and result in pronounced extra peak in the impurity spectral function up to temperatures as high as 20 K.Comment: Accepted in Phys. Rev.

    Hérnia Diafragmática Congénita. Casuística de 10 Anos

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    Os autores fizeram a revisão dos casos de hérnia diafragmática congénita admitidos na Unidade de Cuidados Intensivos Neonatais do Hospital de Dona Estefânia de Janeiro de 1984 a Dezembro de 1993 (10 anos). Neste período foram internados 53 recém-nascidos (RN) com hérnia diafragmática congénita tipo Bochdalek. A pesquisa incidiu sobre os índices de gravidade clínicos, radiológico, ventilatório, de oxigenação e mortalidade. Em 54,7% dos RN houve asfixia neonatal. A dificuldade respiratória teve início antes das 6 horas de vida em 43 dos RN (81.1%), mas o início dos sintomas foi imediato em 31. A hérnia localizava-se à esquerda em 77.4% dos casos. Em 5 casos não foi possível a correcção cirúrgia do defeito diafragmático. A mortalidade global foi 47.2%. Dos 48 RN operados faleceram 20 (41.7%). Em todas as crianças que faleceram, excepto numa, houve início imediato dos sintomas. A mortalidade dos RN com índice radiológico >6 foi de 81.5%. O índice ventilatório >1000 e o índice de oxigenação >40 tiveram valor preditivo de morte (mortalidade de 100% em ambos os casos). Nesta casuística, os achados que melhor se correlacionaram com o prognóstico foram: início imediato dos sintomas, I.R. >6, I.V.> 1000 e I.O.> 40

    Toxicity and effects of copper sulfate on parasitic control and hematological response of tambaqui Colossoma macropomum.

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    The purpose of this work was to determine the mean lethal concentration (LC50-96h) of copper sulfate (CuSO4) for juveniles Colossoma macropomum (Characidae), to evaluate the effectiveness of different concentrations of CuSO4 on elimination of parasites, as well as to study the effects of CuSO4 on blood parameters after short-term exposure. After determination of the LC50-96h from 17.5 mg L-1 of CuSO4, it was investigated the effects of exposure for 48 h to 1.75, 4.37 and 8.75 mg L-1 of CuSO4, on parasites and blood parameters. In gills and skin, concentrations of 4.37 and 8.75 mg L-1 of CuSO4 eliminated Monogenoidea Anacanthorus spathulatus. In fish exposed to different concentrations of CuSO4, plasma total protein, chloride, potassium, glucose and copper levels, hemoglobin and hematocrit were similar to controls, whereas sodium levels presented decrease in fish exposed to 1.75 and 4.37 mg L-1. Red blood cell counts decreased in fish exposed to different three concentrations of CuSO4, while the Mean Corpuscular Volume (MCV) increased. However, exposure to 8.75 mg L-1 of CuSO4 caused decrease on total leukocytes, lymphocytes, neutrophils and PAS-positive granular leukocytes (PAS-GL) number when compared to control fish
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