Limits on excited tau leptons masses from leptonic tau decays

We study the effects induced by excited leptons on the leptonic tau decay at one loop level. Using a general effective lagrangian approach to describe the couplings of the excited leptons, we compute their contributions to the leptonic decays and use the current experimental values of the branching ratios to put limits on the mass of excited states and the substructure scale.Comment: 10 pages, 6 figures, to be published in Phys. Rev.

Influência de variáveis climáticas sobre o comportamento ingestivo de vacas de corte no Pantanal.

Estudos sobre o comportamento animal em condições naturais são fundamentais para definição de critérios de bem-estar animal. Este teve como objetivo avaliar a influência de variáveis climáticas sobre o comportamento ingestivo de vacas de cria criadas em pastagens nativa na sub-região da Nhecolândia, Pantanal, no período de 2002 a 2004

Uso do índice de valor forrageiro na avaliação da qualidade de pastagens nativas do Pantanal.

Este estudo teve como objetivo usar o índice de valor forrageiro na avaliação e monitoramento da qualidade das principais pastagens nativas usadas por bovinos na sub-região da Nhecolândia, Pantanal, de outubro de 1997 a setembro de 1999. Para estabelecer critérios de referência, efetuou-se a determinação do IVF nos principais sítios de pastejo selecionados por bovinos, que foram agrupadas em campo limpo e áreas baixas

Synthesis of new Fe(II) and Ru(II) eta(5)-monocyclopentadienyl compounds showing significant second order NLO properties

A series of new ruthenium(II) complexes of the general formula [Ru(eta(5)-C5H5)(PP)(L)][PF6] (PP = DPPE or 2PPh(3), L = 4-butoxybenzonitrile or N-(3-cyanophenyl)formamide) and the binuclear iron(II) complex [Fe(eta(5)-C5H5)(PP)(mu-L)(PP)(eta(5)-C5H5)Fe][PF6](2) (L = (E)-2-(3-(4-nitrophenyl)allylidene)malononitrile, that has been also newly synthesized) have been prepared and studied to evaluate their potential in the second harmonic generation property. All the new compounds were fully characterized by NMR, IR and UV-Vis spectroscopies and their electrochemistry behaviour was studied by cyclic voltammetry. Quadratic hyperpolarizabilities (beta) of three of the complexes have been determined by hyper-Rayleigh scattering (HRS) measurements at fundamental wavelength of 1500 nm and the calculated static beta(0) values are found to fall in the range 65-212 x 10(-30) esu. Compound presenting beta(0) = 212 x 10(-30) esu has revealed to be 1.2 times more efficient than urea standard in the second harmonic generation (SHG) property, measured in the solid state by Kurtz powder technique, using a Nd:YAG laser (1064 nm). (C) 2013 Elsevier B.V. All rights reserved

QCD and SUSY-QCD corrections to the Three-Body Decay of the Charged Higgs Boson

The ${\cal O}(\alpha_s)$ QCD corrections to the three-body decay width of the charged Higgs $\Gamma$($H^+\to W^+b\bar{b}$) are discussed in the MSSM model. Our calculations indicate that the standard QCD corrections to the three-body decay mode raise the width by about 12% and the supersymmetric QCD corrections(due to $\tilde{g}, \tilde{t}, \tilde{b}$ exchanges) can be comparable to or even larger than the standard QCD corrctions in some regions of the supersymmetric parameter space. This is mainly due to the effect of large left-right mixing of stop($\tilde{t}$). It could significantly affect the phenomenology of the $H^+$ search.Comment: 14 pages, 14figure

Ionized gas kinematics of galaxies in the CALIFA survey I: Velocity fields, kinematic parameters of the dominant component, and presence of kinematically distinct gaseous systems

This work provides an overall characterization of the kinematic behavior of the ionized gas of the galaxies included in the Calar Alto Legacy Integral field Area (CALIFA), offering kinematic clues to potential users of this survey for including kinematical criteria for specific studies. From the first 200 galaxies observed by CALIFA, we present the 2D kinematic view of the 177 galaxies satisfying a gas detection threshold. After removing the stellar contribution, we used the cross-correlation technique to obtain the radial velocity of the dominant gaseous component. The main kinematic parameters were directly derived from the radial velocities with no assumptions on the internal motions. Evidence of the presence of several gaseous components with different kinematics were detected by using [OIII] profiles. Most objects in the sample show regular velocity fields, although the ionized-gas kinematics are rarely consistent with simple coplanar circular motions. 35% of the objects present evidence of a displacement between the photometric and kinematic centers larger than the original spaxel radii. Only 17% of the objects in the sample exhibit kinematic lopsidedness when comparing receding and approaching sides of the velocity fields, but most of them are interacting galaxies exhibiting nuclear activity. Early-type galaxies in the sample present clear photometric-kinematic misaligments. There is evidence of asymmetries in the emission line profiles suggesting the presence of kinematically distinct gaseous components at different distances from the nucleus. This work constitutes the first determination of the ionized gas kinematics of the galaxies observed in the CALIFA survey. The derived velocity fields, the reported kinematic peculiarities and the identification of the presence of several gaseous components might be used as additional criteria for selecting galaxies for specific studies.Comment: 38 pages, 16 figures, 4 tables. Paper accepted for publication in A&

Time Delays on Carotid Endarterectomy: Institutional Experience and Improvement Strategies

Objetivos: Avaliar as vias de referenciação dos doentes com estenoses carotídeas sintomáticas que foram operados na nossa instituição; estruturar os tempos de espera desde os primeiros sintomas neurológicos à data da cirurgia; identificar os fatores responsáveis pelos atrasos e criar estratégias que permitam reduzi-los. Material e métodos: Realizou-se um estudo observacional retrospetivo de todos os doentes com estenoses carotídeas sintomáticas submetidas a endarterectomia carotídea na nossa instituição entre 2011-2013. Foram identificadas as etapas essenciais no processo de referenciação dos doentes e foram colhidos dados referentes às datas do início dos sintomas, primeiro contacto médico, exames de imagem vascular, referenciação ao cirurgião, consulta de cirurgia vascular e da endarterectomia carotídea. O tempo decorrido entre o evento neurológico e a cirurgia foi calculado em dias e todos os atrasos identificados foram analisados detalhadamente. Resultados: A mediana do tempo de espera do evento neurológico à cirurgia foi de 27,5 dias (intervalo 7-581).Os maiores atrasos verificaram-se entre a data em que é colocada a indicação cirúrgica e a endarterectomia carotídea (mediana 9 dias; intervalo 1-349); na referenciação dos doentes à consultadecirurgia vascular (mediana 6,5 dias; intervalo 0-97)e entre o primeiro contacto médico e a realização dos exames de imagem vascular (mediana 6 dias; intervalo 1-71). Dos 60 doentes incluídos, apenas 21,7% foram operados nos primeiros 14 dias após o evento neurológico. O atraso foi significativamente menor nos doentes admitidos de forma urgente por transferência inter/intra-hospitalar (n=30; mediana 15 dias, intervalo 7-163) comparativamente aos doentes admitidos eletivamente pela consulta (n=30; mediana 86 dias, intervalo 13-581 dias) (p<0,0001).Discussão: Apesar da evidência atual, ainda existem atrasos significativos no processo de referenciação dos doentes com estenoses carotídeas sintomáticas. Estratégias direcionadas à redução destes atrasos poderão aumentar substancialmente a proporção de doentes submetidos a endarterectomia carotídea até 14 dias após o evento neurológico inicial

Noncommutative cosmological models coupled to a perfect fluid and a cosmological constant

In this work we carry out a noncommutative analysis of several Friedmann-Robert-Walker models, coupled to different types of perfect fluids and in the presence of a cosmological constant. The classical field equations are modified, by the introduction of a shift operator, in order to introduce noncommutativity in these models. We notice that the noncommutative versions of these models show several relevant differences with respect to the correspondent commutative ones.Comment: 27 pages. 7 figures. JHEP style.arXiv admin note: substantial text overlap with arXiv:1104.481

Stellar Population gradients in galaxy discs from the CALIFA survey

While studies of gas-phase metallicity gradients in disc galaxies are common, very little has been done in the acquisition of stellar abundance gradients in the same regions. We present here a comparative study of the stellar metallicity and age distributions in a sample of 62 nearly face-on, spiral galaxies with and without bars, using data from the CALIFA survey. We measure the slopes of the gradients and study their relation with other properties of the galaxies. We find that the mean stellar age and metallicity gradients in the disc are shallow and negative. Furthermore, when normalized to the effective radius of the disc, the slope of the stellar population gradients does not correlate with the mass or with the morphological type of the galaxies. Contrary to this, the values of both age and metallicity at $\sim$2.5 scale-lengths correlate with the central velocity dispersion in a similar manner to the central values of the bulges, although bulges show, on average, older ages and higher metallicities than the discs. One of the goals of the present paper is to test the theoretical prediction that non-linear coupling between the bar and the spiral arms is an efficient mechanism for producing radial migrations across significant distances within discs. The process of radial migration should flatten the stellar metallicity gradient with time and, therefore, we would expect flatter stellar metallicity gradients in barred galaxies. However, we do not find any difference in the metallicity or age gradients in galaxies with without bars. We discuss possible scenarios that can lead to this absence of difference.Comment: 24 pages, 17 figures, accepted for publication in A&