372 research outputs found

    Phenomenological Consequences of sub-leading Terms in See-Saw Formulas

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    Several aspects of next-to-leading (NLO) order corrections to see-saw formulas are discussed and phenomenologically relevant situations are identified. We generalize the formalism to calculate the NLO terms developed for the type I see-saw to variants like the inverse, double or linear see-saw, i.e., to cases in which more than two mass scales are present. In the standard type I case with very heavy fermion singlets the sub-leading terms are negligible. However, effects in the percent regime are possible when sub-matrices of the complete neutral fermion mass matrix obey a moderate hierarchy, e.g. weak scale and TeV scale. Examples are cancellations of large terms leading to small neutrino masses, or inverse see-saw scenarios. We furthermore identify situations in which no NLO corrections to certain observables arise, namely for mu-tau symmetry and cases with a vanishing neutrino mass. Finally, we emphasize that the unavoidable unitarity violation in see-saw scenarios with extra fermions can be calculated with the formalism in a straightforward manner.Comment: 22 pages, matches published versio

    Distances from the Correlation between Galaxy Luminosities and Rotation Rates

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    A large luminosity--linewidth template sample is now available, improved absorption corrections have been derived, and there are a statistically significant number of galaxies with well determined distances to supply the zero point. A revised estimate of the Hubble Constant is H_0=77 +-4 km/s/Mpc where the error is the 95% probability statistical error. Systematic uncertainties are potentially twice as large.Comment: 21 pages, 9 figures. Invited chapter for the book `Post-Hipparcos Cosmic Candles', Eds. F. Caputo and A. Heck (Kluwer Academic Publishers, Dordrecht

    Non-standard interactions versus non-unitary lepton flavor mixing at a neutrino factory

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    The impact of heavy mediators on neutrino oscillations is typically described by non-standard four-fermion interactions (NSIs) or non-unitarity (NU). We focus on leptonic dimension-six effective operators which do not produce charged lepton flavor violation. These operators lead to particular correlations among neutrino production, propagation, and detection non-standard effects. We point out that these NSIs and NU phenomenologically lead, in fact, to very similar effects for a neutrino factory, for completely different fundamental reasons. We discuss how the parameters and probabilities are related in this case, and compare the sensitivities. We demonstrate that the NSIs and NU can, in principle, be distinguished for large enough effects at the example of non-standard effects in the μ\mu-τ\tau-sector, which basically corresponds to differentiating between scalars and fermions as heavy mediators as leading order effect. However, we find that a near detector at superbeams could provide very synergistic information, since the correlation between source and matter NSIs is broken for hadronic neutrino production, while NU is a fundamental effect present at any experiment.Comment: 32 pages, 5 figures. Final version published in JHEP. v3: Typo in Eq. (27) correcte

    Phenomenology and Cosmology of an Electroweak Pseudo-Dilaton and Electroweak Baryons

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    In many strongly-interacting models of electroweak symmetry breaking the lowest-lying observable particle is a pseudo-Goldstone boson of approximate scale symmetry, the pseudo-dilaton. Its interactions with Standard Model particles can be described using a low-energy effective nonlinear chiral Lagrangian supplemented by terms that restore approximate scale symmetry, yielding couplings of the pseudo-dilaton that differ from those of a Standard Model Higgs boson by fixed factors. We review the experimental constraints on such a pseudo-dilaton in light of new data from the LHC and elsewhere. The effective nonlinear chiral Lagrangian has Skyrmion solutions that may be identified with the `electroweak baryons' of the underlying strongly-interacting theory, whose nature may be revealed by the properties of the Skyrmions. We discuss the finite-temperature electroweak phase transition in the low-energy effective theory, finding that the possibility of a first-order electroweak phase transition is resurrected. We discuss the evolution of the Universe during this transition and derive an order-of-magnitude lower limit on the abundance of electroweak baryons in the absence of a cosmological asymmetry, which suggests that such an asymmetry would be necessary if the electroweak baryons are to provide the cosmological density of dark matter. We revisit estimates of the corresponding spin-independent dark matter scattering cross section, with a view to direct detection experiments.Comment: 34 pages, 4 figures, additional references adde

    Probing top charged-Higgs production using top polarization at the Large Hadron Collider

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    We study single top production in association with a charged Higgs in the type II two Higgs doublet model at the Large Hadron Collider. The polarization of the top, reflected in the angular distributions of its decay products, can be a sensitive probe of new physics in its production. We present theoretically expected polarizations of the top for top charged-Higgs production, which is significantly different from that in the closely related process of t-W production in the Standard Model. We then show that an azimuthal symmetry, constructed from the decay lepton angular distribution in the laboratory frame, is a sensitive probe of top polarization and can be used to constrain parameters involved in top charged-Higgs production.Comment: 22 pages, 18 Figures, Discussions about backgrounds and NLO corrections added, figures modified, references added, Version published in JHE

    Decoupling property of the supersymmetric Higgs sector with four doublets

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    In supersymmetric standard models with multi Higgs doublet fields, selfcoupling constants in the Higgs potential come only from the D-terms at the tree level. We investigate the decoupling property of additional two heavier Higgs doublet fields in the supersymmetric standard model with four Higgs doublets. In particular, we study how they can modify the predictions on the quantities well predicted in the minimal supersymmetric standard model (MSSM), when the extra doublet fields are rather heavy to be measured at collider experiments. The B-term mixing between these extra heavy Higgs bosons and the relatively light MSSM-like Higgs bosons can significantly change the predictions in the MSSM such as on the masses of MSSM-like Higgs bosons as well as the mixing angle for the two light CP-even scalar states. We first give formulae for deviations in the observables of the MSSM in the decoupling region for the extra two doublet fields. We then examine possible deviations in the Higgs sector numerically, and discuss their phenomenological implications.Comment: 26 pages, 24 figures, text sligtly modified,version to appear in Journal of High Energy Physic

    A review of elliptical and disc galaxy structure, and modern scaling laws

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    A century ago, in 1911 and 1913, Plummer and then Reynolds introduced their models to describe the radial distribution of stars in `nebulae'. This article reviews the progress since then, providing both an historical perspective and a contemporary review of the stellar structure of bulges, discs and elliptical galaxies. The quantification of galaxy nuclei, such as central mass deficits and excess nuclear light, plus the structure of dark matter halos and cD galaxy envelopes, are discussed. Issues pertaining to spiral galaxies including dust, bulge-to-disc ratios, bulgeless galaxies, bars and the identification of pseudobulges are also reviewed. An array of modern scaling relations involving sizes, luminosities, surface brightnesses and stellar concentrations are presented, many of which are shown to be curved. These 'redshift zero' relations not only quantify the behavior and nature of galaxies in the Universe today, but are the modern benchmark for evolutionary studies of galaxies, whether based on observations, N-body-simulations or semi-analytical modelling. For example, it is shown that some of the recently discovered compact elliptical galaxies at 1.5 < z < 2.5 may be the bulges of modern disc galaxies.Comment: Condensed version (due to Contract) of an invited review article to appear in "Planets, Stars and Stellar Systems"(www.springer.com/astronomy/book/978-90-481-8818-5). 500+ references incl. many somewhat forgotten, pioneer papers. Original submission to Springer: 07-June-201

    Continuous increase of cardiovascular diseases, diabetes, and non-HIV related cancers as causes of death in HIV-infected individuals in Brazil: An analysis of nationwide data

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    Introduction: After antiretroviral therapy (ART) became available, there was a decline in the number of deaths in persons infected with HIV. Thereafter, there was a decrease in the proportion of deaths attributed to opportunistic infections and an increase in the proportion of deaths attributed to chronic comorbidities. Herein we extend previous observations from a nationwide survey on temporal trends in causes of death in HIV-infected patients in Brazil. Methods: We describe temporal trends in causes of death among adults who had HIV/AIDS listed in the death certificate to those who did not. All death certificates issued in Brazil from 1999 to 2011 and listed in the national mortality database were included. Generalized linear mixed-effects logistic models were used to study temporal trends in proportions. Results: In the HIV-infected population, there was an annual adjusted average increase of 6.0%, 12.0%, 4.0% and 4.1% for cancer, external causes, cardiovascular diseases (CVD) and diabetes mellitus (DM), respectively, compared to 3.0%, 4.0%, 1.0% and 3.9%, in the non-HIV group. For tuberculosis (TB), there was an adjusted average increase of 0.3%/year and a decrease of 3.0%/year in the HIV and the non-HIV groups, respectively. Compared to 1999, the odds ratio (OR) for cancer, external causes, CVD, DM, or TB in the HIV group were, respectively, 2.31, 4.17, 1.76, 2.27 and 1.02, while for the non-HIV group, the corresponding OR were 1.31, 1.63, 1.14, 1.62 and 0.67. Interactions between year as a continuous or categorical variable and HIV were significant (p <0.001) for all conditions, except for DM when year was considered as a continuous variable (p = 0.76). Conclusions: Non HIV-related co-morbidities continue to increase more rapidly as causes of death among HIV-infected individuals than in those without HIV infection, highlighting the need for targeting prevention measures and surveillance for chronic diseases among those patients. © 2014 Paula et al

    Metabolism of Gamma-Benzene Hexachloride in the Animal Body

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    Impacto da técnica de expiração lenta e prolongada na mecânica respiratória de lactentes sibilantes

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    OBJECTIVE: To evaluate changes in respiratory mechanics and tidal volume (V T) in wheezing infants in spontaneous ventilation after performing the technique known as the prolonged, slow expiratory (PSE) maneuver. METHODS: We included infants with a history of recurrent wheezing and who had had no exacerbations in the previous 15 days. For the assessment of the pulmonary function, the infants were sedated and placed in the supine position, and a face mask was used and connected to a pneumotachograph. The variables of tidal breathing (V T and RR) as well as those of respiratory mechanics-respiratory system compliance (Crs), respiratory system resistance (Rrs), and the respiratory system time constant (prs)-were measured before and after three consecutive PSE maneuvers. RESULTS: We evaluated 18 infants. The mean age was 32 ± 11 weeks. After PSE, there was a significant increase in V T (79.3 ± 15.6 mL vs. 85.7 ± 17.2 mL; p = 0.009) and a significant decrease in RR (40.6 ± 6.9 breaths/min vs. 38.8 ± 0,9 breaths/min; p = 0.042). However, no significant differences were found in the variables of respiratory mechanics (Crs: 11.0 ± 3.1 mL/cmH2O vs. 11.3 ± 2.7 mL/cmH2O; Rrs: 29.9 ± 6.2 cmH2O mL-1 s-1 vs. 30.8 ± 7.1 cmH2O mL-1 s-1; and prs: 0.32 ± 0.11 s vs. 0.34 ±0.12 s; p > 0.05 for all). CONCLUSIONS: This respiratory therapy technique is able to induce significant changes in V T and RR in infants with recurrent wheezing, even in the absence of exacerbations. The fact that the variables related to respiratory mechanics remained unchanged indicates that the technique is safe to apply in this group of patients. Studies involving symptomatic infants are needed in order to quantify the functional effects of the technique.OBJETIVO: Avaliar as alterações da mecânica respiratória e do volume corrente (VC) em lactentes sibilantes em ventilação espontânea após a realização da técnica de expiração lenta e prolongada (ELPr). MÉTODOS: Foram incluídos no estudo lactentes com história de sibilância recorrente e sem exacerbações nos 15 dias anteriores. Para a avaliação da função pulmonar, os lactentes foram sedados e posicionados em decúbito dorsal com máscara facial acoplada a um pneumotacógrafo. As variáveis da respiração corrente - VC e FR - e da mecânica respiratória - complacência do sistema respiratório (Csr), resistência (Rsr) e constante de tempo (psr) - foram mensuradas antes e após a realização de três sequências consecutivas de ELPr. RESULTADOS: Foram avaliados 18 lactentes, com média de idade de 32 ± 11 semanas. Houve um aumento significante no VC após ELPr (79,3 ± 15,6 mL vs. 85,7 ± 17,2 mL; p = 0,009), assim como uma redução na FR (40,6 ± 6,9 ciclos/min vs. 38,8 ± 0,9 ciclos/min; p = 0,042). Entretanto, não houve alterações significantes nos valores da mecânica respiratória (Csr: 11,0 ± 3,1 mL/cmH2O vs. 11,3 ± 2,7 mL/cmH2O; Rsr: 29,9 ± 6,2 cmH2O mL-1 s-1 vs. 30,8 ± 7,1 cmH2O mL-1 s-1; e psr: 0,32 ± 0,11 s vs. 0,34 ± 0,12 s; p > 0,05 para todos). CONCLUSÕES: Essa técnica de fisioterapia respiratória é capaz de induzir alterações significativas no VC e na FR de lactentes com sibilância recorrente, mesmo na ausência de exacerbações. A manutenção das variáveis da mecânica respiratória indica que a técnica é segura para ser aplicada nesse grupo de pacientes. Estudos com lactentes sintomáticos são necessários para quantificar os efeitos funcionais da técnica.Universidade Nove de Julho Programa de Pós Graduação em Ciências da ReabilitaçãoUniversidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Departamento de PediatriaUniversidade Federal de São Paulo (UNIFESP) Escola Paulista de MedicinaHospital Israelita Albert Einstein Setor de Pediatria e NeonatologiaUNIFESP, EPM, Depto. de PediatriaUNIFESP, EPMSciEL
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