9,305 research outputs found

    Lepton Flavor Violation and Collider Searches in a Type I + II Seesaw Model

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    Neutrino are massless in the Standard Model. The most popular mechanism to generate neutrino masses are the type I and type II seesaw, where right-handed neutrinos and a scalar triplet are augmented to the Standard Model, respectively. In this work, we discuss a model where a type I + II seesaw mechanism naturally arises via spontaneous symmetry breaking of an enlarged gauge group. Lepton flavor violation is a common feature in such setup and for this reason, we compute the model contribution to the μeγ\mu \rightarrow e\gamma and μ3e\mu \rightarrow 3e decays. Moreover, we explore the connection between the neutrino mass ordering and lepton flavor violation in perspective with the LHC, HL-LHC and HE-LHC sensitivities to the doubly charged scalar stemming from the Higgs triplet. Our results explicitly show the importance of searching for signs of lepton flavor violation in collider and muon decays. The conclusion about which probe yields stronger bounds depends strongly on the mass ordering adopted, the absolute neutrino masses and which much decay one considers. In the 1-5 TeV mass region of the doubly charged scalar, lepton flavor violation experiments and colliders offer orthogonal and complementary probes. Thus if a signal is observed in one of the two new physics searches, the other will be able to assess whether it stems from a seesaw framework.Comment: 41 pages, 1 figure, 2 table

    Some Remarks about Variable Mass Systems

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    We comment about the general argument given to obtain the rocket equation as it is exposed in standard textbooks. In our opinion, it can induce students to a wrong answer when solving variable mass problems.Comment: 2 page

    Previous purification of seminal plasma proteins from goats through Sephadex G-25 and G25-80.

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    Edição dos Abstracts do II International Symposium on animal Biology or Reproduction, São Paulo, nov. 2008

    Alterações renais funcionais em caprinos submetidos a infusão intravenosa de hemolisado.

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    Resumo: 0 presente estudo foi realizado em 32 caprinos, adultos, Sem Raça Definida (SRD), sendo 16 machos e 16 fêmeas, com propósito de constatar a existência de alteraçoes funcionais renais em caprinos submetidos à aplicaçào intravenosa de hemolisado, através de quantificação dos níveis séricos de uréia e creatinina. Constituiram-se 4 grupos, cada um composto de 8 animais, dos quais 5 foram submetidos a infusao de hemolisado e 3 permaneceram como controle. Nos animais os grupos l, II e III retiraram-se volumes sangüíneos respectivamente a 5, 10 e 15 ml/kg de peso corpóreo. Cada animal do grupo hemólise recebeu, por via intravenosa lenta, após ruptura mecânica das hemacias por congelamento, o hemolisado em igual volume ao sangue retirado. Os animais controle receberam, também por via intravenosa lenta, soluçao satine fisiológica a 0,87% em igual volume ao do sangue retirado. No grupo IV, realizou-se a sangria de 10 ml/kg de peso, e a reposição do hemolisado se fez na dose de 2,5 ml/kg de peso vivo, corn intervalos de 48 haras. Os resultados encontrados nas diferentes dosagens administradas, permitiram concluir que, ao nível tubular, houve alteraçoes funcionais, demonstradas pela exame de urina (glicosúria, hemoglobinúria e tendência e isostenúria) e que, ao nível glomerular, não houve alterações de fluxo nem de função que pudessem ser identificadas através da determinação dos níveis de uréia e creatinina sérica

    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

    Non-adiabatic radiative collapse of a relativistic star under different initial conditions

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    We examine the role of space-time geometry in the non-adiabatic collapse of a star dissipating energy in the form of radial heat flow, studying its evolution under different initial conditions. The collapse of a star with interior comprising of a homogeneous perfect fluid is compared with that of a star filled with inhomogeneous imperfect fluid with anisotropic pressure. Both the configurations are spherically symmetric, however, in the latter case, the physical space t=constantt= constant of the configurations is assumed to be inhomogeneous endowed with spheroidal or pseudo-spheroidal geometry. It is observed that as long as the collapse is shear-free, its evolution depends only on the mass and size of the star at the onset of collapse.Comment: To appear in Pramana- j. of physic
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