3,524 research outputs found
Wrong sign and symmetric limits and non-decoupling in 2HDMs
We analyse the possibility that, in two Higgs doublet models, one or more of
the Higgs couplings to fermions or to gauge bosons change sign, relative to the
respective Higgs Standard Model couplings. Possible sign changes in the
coupling of a neutral scalar to charged ones are also discussed. These
\textit{wrong signs} can have important physical consequences, manifesting
themselves in Higgs production via gluon fusion or Higgs decay into two gluons
or into two photons. We consider all possible wrong sign scenarios, and also
the \textit{symmetric limit}, in all possible Yukawa implementations of the two
Higgs doublet model, in two different possibilities: the observed Higgs boson
is the lightest CP-even scalar, or the heaviest one. We also analyse thoroughly
the impact of the currently available LHC data on such scenarios. With all 8
TeV data analysed, all wrong sign scenarios are allowed in all Yukawa types,
even at the 1 level. However, we will show that B-physics constraints
are crucial in excluding the possibility of wrong sign scenarios in the case
where is below 1. We will also discuss the future prospects for
probing the wrong sign scenarios at the next LHC run. Finally we will present a
scenario where the alignment limit could be excluded due to non-decoupling in
the case where the heavy CP-even Higgs is the one discovered at the LHC.Comment: 20 pages, 15 figure
The CP-conserving 2HDM after the 8 TeV run
We confront the most common CP-conserving 2HDM with the LHC data analysed so
far while taking into account all previously available experimental data. A
special allowed corner of the parameter space is analysed - the so-called
wrong-sign scenario where the Higgs coupling to down-type quarks changes sign
relative to the Standard Model while the coupling to the massive vector bosons
does not.Comment: 6 pages, 2 figures, to appear in the proceedings of the 22nd
International Workshop on Deep-Inelastic Scattering and Related Subjects (DIS
2014), 28 April - 2 May 2014 Warsaw (Poland
Active Metal Brazing of Machinable Aluminum Nitride-Based Ceramic to Stainless Steel
Shapal!-M machinable AlN-based ceramic and AISI 304 stainless steel were joined by active metal
brazing, at 750, 800, and 850 !C, with a dwell stage of 10 min at the processing temperature, using a 59Ag-
27.25Cu-12.5In-1.25Ti (wt.%) filler foil. The influences of temperature on the microstructural features of
brazed interfaces and on the shear strength of joints were assessed. The interfacial microstructures were
analyzed by scanning electron microscopy (SEM), and the composition of the phases detected at the
interfaces was evaluated by energy dispersive X-ray spectroscopy (EDS). The fracture surfaces of joints
were analyzed by SEM, EDS, and GIXRD (Grazing Incidence X-Ray Diffraction). Reaction between the
liquid braze and both base materials led to the formation of a Ti-rich layer, adjacent to each base material.
Between the Ti-rich layers, the interfaces consist of a (Ag) solid-solution matrix, where coarse (Cu) particles
and either Cu-In or Cu-In-Ti and Cu-Ti intermetallics phases are dispersed. The stronger joints, with shear
strength of 220±32 MPa, were produced after brazing at 800 !C. Fracture of joints occurred preferentially
not only through the ceramic sample but also across the adjoining TiN layer, independent of the
brazing temperature
The Wrong Sign limit in the 2HDM
A sign change in the Higgs couplings to fermions and massive gauge bosons is
still allowed in the framework of two-Higgs doublet models (2HDM). In this work
we discuss the possible sign changes in the Higgs couplings to fermions and
gauge bosons, while reviewing the status of the 8-parameter CP-conserving 2HDM
after the Large Hadron Collider 8 TeV run.Comment: 6 pages, 3 figures. Proceedings of the Second Annual Conference on
Large Hadron Collider Physics, Columbia University, New York, U.S.A, June
2-7, 2014. arXiv admin note: text overlap with arXiv:1407.439
A Educação ambiental como instrumento para a melhoria da gestão dos resíduos sólidos nas organizações públicas e privadas: contexto, legislação e ações estratégicas.
Este trabalho parte de um problema do presente, o alto consumo de bens materiais e seus desperdícios nas organizações públicas e privadas, e se propõe a oferecer diretrizes em educação ambiental para administrar e diminuir a produção de resíduos sólidos comuns, como papel, plástico, vidro e metal. Na Empresa Brasileira de Pesquisa Agropecuária (Embrapa), no Estado do Amapá, desenvolve-se um programa de gestão ambiental, cuja ênfase no gerenciamento desses resíduos está em fase de implementação, com a construção de uma área para processamento do lixo produzido diariamente. Dessa forma, o objetivo geral deste documento é apresentar uma pequena abordagem sobre a evolução da questão ambiental, sugerindo ações para a redução do consumo de materiais diversos nas instituições, tendo a educação ambiental como instrumento estratégico para internalizar os procedimentos de melhoria da qualidade do meio ambiente no trabalho, conduzindo os servidores a uma mudança de comportamento, na busca de soluções concretas para as alterações nos padrões insustentáveis da vida moderna.bitstream/item/62290/1/AP-2012-Educacao-ambiental-Documentos-73.pd
Large and small-scale structures and the dust energy balance problem in spiral galaxies
The interstellar dust content in galaxies can be traced in extinction at
optical wavelengths, or in emission in the far-infrared. Several studies have
found that radiative transfer models that successfully explain the optical
extinction in edge-on spiral galaxies generally underestimate the observed
FIR/submm fluxes by a factor of about three. In order to investigate this
so-called dust energy balance problem, we use two Milky Way-like galaxies
produced by high-resolution hydrodynamical simulations. We create mock optical
edge-on views of these simulated galaxies (using the radiative transfer code
SKIRT), and we then fit the parameters of a basic spiral galaxy model to these
images (using the fitting code FitSKIRT). The basic model includes smooth
axisymmetric distributions along a S\'ersic bulge and exponential disc for the
stars, and a second exponential disc for the dust. We find that the dust mass
recovered by the fitted models is about three times smaller than the known dust
mass of the hydrodynamical input models. This factor is in agreement with
previous energy balance studies of real edge-on spiral galaxies. On the other
hand, fitting the same basic model to less complex input models (e.g. a smooth
exponential disc with a spiral perturbation or with random clumps), does
recover the dust mass of the input model almost perfectly. Thus it seems that
the complex asymmetries and the inhomogeneous structure of real and
hydrodynamically simulated galaxies are a lot more efficient at hiding dust
than the rather contrived geometries in typical quasi-analytical models. This
effect may help explain the discrepancy between the dust emission predicted by
radiative transfer models and the observed emission in energy balance studies
for edge-on spiral galaxies.Comment: 9 pages, 5 figures, accepted for publication in A&
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