On Composite Two Higgs Doublet Models

We investigate composite two Higgs doublet models realized as pseudo Goldstone modes, generated through the spontaneous breaking of a global symmetry due to strong dynamic at the TeV scale. A detailed comparative survey of two possible symmetry breaking patterns, SU(5) -> SU(4) x U(1) and SU(5) x SU(4), is made. We point out choices for the Standard Model fermion representations that can alleviate some phenomenological constraints, with emphasis towards a simultaneous solution of anomalous Zb\bar{b} coupling and Higgs mediated Flavor Changing Neutral Currents. We also write down the kinetic lagrangian for several models leading to Two Higgs Doublets and identify the anomalous contributions to the T parameter. Moreover, we describe a model based on the breaking $SO(9)/SO(8)$ in which there is no tree-level breaking of custodial symmetry, discussing also the possible embeddings for the fermion fields.Comment: 17 pages. Mistake corrected, added one section on a T- and flavor safe model based on SO(9)/SO(8). Matches published versio

Search for light custodians in a clean decay channel at the LHC

Models of warped extra dimensions with custodial symmetry usually predict the existence of a light Kaluza-Klein fermion arising as a partner of the right-handed top quark, sometimes called light custodians which we will denote $\tilde{b}_R$. The production of these particles at the LHC can give rise to multi-W events which could be observed in same-sign dilepton channels, but its mass reconstruction is challenging. In this letter we study the possibility of finding a signal for the pair production of this new particle at the LHC focusing on a rarer, but cleaner decay mode of a light custodian into a $Z$ boson and a $b$-quark. In this mode it would be possible to reconstruct the light custodian mass. In addition to the dominant standard model QCD production processes, we include the contribution of a Kaluza-Klein gluon first mode. We find that the $\tilde{b}_R$ stands out from the background as a peak in the $b Z$ invariant mass. However, when taking into account only the electronic and muonic decay modes of the $Z$ boson and $b-$tagging efficiencies, the LHC will have access only to the very light range of masses, $m_{\tilde{b}} = {\cal O} (500)$ GeV.Comment: 8 pages, 2 figure

Distinguishing Various Models of the 125 GeV Boson in Vector Boson Fusion

The hint of a new particle around 125 GeV at the LHC through the decay modes of diphoton and a number of others may point to quite a number of possibilities. While at the LHC the dominant production mechanism for the Higgs boson of the standard model and some other extensions is via the gluon fusion process, the alternative vector boson fusion is more sensitive to electroweak symmetry breaking through the gauge-Higgs couplings and therefore can be used to probe for models beyond the standard model. In this work, using the well known dijet-tagging technique to single out the vector boson fusion mechanism, we investigate its capability to discriminate a number of models that have been suggested to give an enhanced inclusive diphoton production rate, including the standard model Higgs boson, fermiophobic Higgs boson, Randall-Sundrum radion, inert-Higgs-doublet model, two-Higgs-doublet model, and the MSSM. The rates in vector-boson fusion can give more information of the underlying models to help distinguishing among the models.Comment: 31 pages, 3 figures; in this version some wordings are change

Breastfeeding : prevalence and determinant factors

Breastfeeding:Prevalence and Determinant Factors Breastfeeding is the best way of feeding the baby for the first six months of life. However, in Portugal the abandonment rate of breastfeeding is very high during the baby first’s months of life. The aim of this study was to assess prevalence of breastfeeding and to identify related factors during the six months after delivery, as sociodemographic variables and life styles. We conducted a cohort study at the Maternity of the Hospital Santa Maria. A standard questionnaire was applied to 475 women after delivery, at three and six months postpartum. We studied socio demographics aspects, life styles and the way of feeding during the six months after delivery. Multivariate analysis was performed. The women studied (mean age of 29,8 +/- 5,4 years), 52,2% were primiparous, 86,1% were Caucasian, 40% had a high school degree and 33% had a University degree. Four hundred and sixty (96,8%) received prenatal care. The mean gestational age was 38,8 +/- 2 weeks and the birth weight was 3198,3 +/- 545,3 g. At the discharge 91% were breastfeeding (77% exclusively), 54,7% at third month and 34,1% at sixth month. The main causes pointed for abandoning breastfeeding were insufficient milk production, bad sucking and return to work. The milk formula introduction was in 68,6% cases by medical recommendation. The decision in maintenance breastfeeding at third and sixth months was correlated with a previous positive breastfeed experience, high educational level, healthy lifestyles, as non-smoking, regular physical activity, and information about advantage of breastfeed for mother health. Information about breastfeeding was received by media, friends, family and only 9% by health professionals. Fifty (13%) women had no information about breastfeeding. Although breastfeeding rate at discharge was high, there was an important rate of abandonment at third and sixth month. Healthy lifestyles, high educational level, a previous positive breastfeed experience had a positive influence in breastfeeding. Understanding attitudes towards pregnancy and breastfeeding can lead to new strategies for its promotion and maintenance.O leite materno constitui o melhor alimento para o bebé nos primeiros quatro a seis meses de vida. No entanto, em Portugal, a taxa de abandono do aleitamento materno é muito importante logo nos primeiros meses de vida do bebé. Objectivos: Avaliar a prevalência do aleitamento materno e identificar factores determinantes da amamentação nos primeiros seis meses pós-parto, nomeadamente características socioeconómicas e estilos de vida. Material e Métodos: Estudo longitudinal prospectivo abrangendo 475 puérperas na Maternidade do Hospital Santa Maria – Lisboa, baseado em questionários directos aplicados no pós-parto, aos 3 e 6 meses. As variáveis incluídas permitiram caracterizar factores socio-económicos, estilos de vida e o tipo de aleitamento nos primeiros seis meses após o parto. Foi realizada análise multivariada. Resultados: Das puérperas estudadas (idade média 29,8 ± 5,4 anos) 52,2 % eram primíparas, 86,1% caucasianas, com escolaridade correspondente ao ensino secundário em 40% e universitário em 33%. A vigilância regular da gravidez ocorreu em 96,8%, a idade gestacional média dos recém nascidos foi de 38,8 ± 2,1 semanas e o peso ao nascer de 3198,3 ± 545,3 gramas. À saída da maternidade, 91% das puérperas amamentavam o seu filho (77,7% em exclusividade) tendo esta percentagem diminuído para 54,7% aos três meses e 34,1% aos seis meses. As causas referidas para o abandono foram a hipo ou agalactia, a má pega e o regresso ao trabalho. De notar que em 68,6% a iniciativa de prescrever a fórmula coube ao médico assistente. A decisão da mulher em manter o aleitamento aos três e aos seis meses foi influenciada pela experiência positiva de amamentar, o nível educacional mais elevado, o não-tabagismo, a prática de exercício físico e a informação sobre as vantagens da amamentação para a saúde materna. A fonte de informação sobre o aleitamento materno coube, por ordem decrescente, aos meios de comunicação, amigos e família e aos profissionais de saúde (9%), sendo que 13% não tinham tido qualquer informação. Conclusão: A taxa de aleitamento materno à saída da maternidade foi elevada mas verificou-se uma acentuada taxa de abandono aos três e aos seis meses. Os estilos de vida saudáveis, o nível educacional elevado e a experiência de amamentar positiva tiveram influência positiva na amamentação. A compreensão das atitudes perante a gravidez e o aleitamento materno pode levar a novas estratégias de intervenção para a sua promoção e manutenção.Trabalho realizado com o apoio dos Laboratórios Abbot Portugal

Paracetamol Induced Acute Interstitial Nephritis: A Pediatric Case Report

N/a

The Higgs as a Probe of Supersymmetric Extra Sectors

We present a general method for calculating the leading contributions to h -> gg and h -> gamma gamma in models where the Higgs weakly mixes with a nearly supersymmetric extra sector. Such mixing terms can play an important role in raising the Higgs mass relative to the value expected in the MSSM. Our method applies even when the extra sector is strongly coupled, and moreover does not require a microscopic Lagrangian description. Using constraints from holomorphy we fix the leading parametric form of the contributions to these Higgs processes, including the Higgs mixing angle dependence, up to an overall coefficient. Moreover, when the Higgs is the sole source of mass for a superconformal sector, we show that even this coefficient is often calculable. For appropriate mixing angles, the contribution of the extra states to h -> gg and h -> gamma gamma can vanish. We also discuss how current experimental limits already lead to non-trivial constraints on such models. Finally, we provide examples of extra sectors which satisfy the requirements necessary to use the holomorphic approximation.Comment: v4: 34 pages, 2 figures, typo corrected and clarification adde

Global Analysis of the Higgs Candidate with Mass ~ 125 GeV

We analyze the properties of the Higgs candidate with mass ~ 125 GeV discovered by the CMS and ATLAS Collaborations, constraining the possible deviations of its couplings from those of a Standard Model Higgs boson. The CMS, ATLAS and Tevatron data are compatible with Standard Model couplings to massive gauge bosons and fermions, and disfavour several types of composite Higgs models unless their couplings resemble those in the Standard Model. We show that the couplings of the Higgs candidate are consistent with a linear dependence on particle masses, scaled by the electroweak scale ~ 246 GeV, the power law and the mass scale both having uncertainties ~ 20%.Comment: 22 pages, 9 figures, v2 incorporates experimental data released during July 2012 and corrected (and improved) treatment of mass dependence of coupling

Gravidez e exercício físico : mitos, evidências e recomendações

In recent years there has been a great increase of scientific research regarding physical exercise during pregnancy. Nevertheless, many doubts persist leading to a decrease of its practice. We aimed to evaluate the main factors that influence the practice of physical activity during pregnancy and mothers’ knowledge regarding its effects. Physical activity has decreased significantly, although it was higher in nulliparous mothers, with higher educational level, employment and between 25 and 34 years old. Mothers who practiced exercise during pregnancy breastfed longer. No correlation was found concerning birth weight, gestational age or obstetric pathology. Although most mothers understand the benefits of physical activity in pregnancy, that doesn’t seem to translate in an increasing practice. We believe there should be an increased awareness of health professionals in order to promote controlled physical exercise in pregnant woman.Trabalho realizado com o apoio do Laboratório Abbott Portugal

Exploring the Higgs Portal with 10/fb at the LHC

We consider the impact of new exotic colored and/or charged matter interacting through the Higgs portal on Standard Model Higgs boson searches at the LHC. Such Higgs portal couplings can induce shifts in the effective Higgs-gluon-gluon and Higgs-photon-photon couplings, thus modifying the Higgs production and decay patterns. We consider two possible interpretations of the current LHC Higgs searches based on ~ 5/fb of data at each detector: 1) a Higgs boson in the mass range (124-126) GeV and 2) a `hidden' heavy Higgs boson which is underproduced due to the suppression of its gluon fusion production cross section. We first perform a model independent analysis of the allowed sizes of such shifts in light of the current LHC data. As a class of possible candidates for new physics which gives rise to such shifts, we investigate the effects of new scalar multiplets charged under the Standard Model gauge symmetries. We determine the scalar parameter space that is allowed by current LHC Higgs searches, and compare with complementary LHC searches that are sensitive to the direct production of colored scalar states.Comment: 27 pages, 11 figures; v2: references added, correction to scalar form factor, numerical results updated with Moriond 2012 data, conclusions unchange