439 research outputs found

    Multi-Scalar-Singlet Extension of the Standard Model - the Case for Dark Matter and an Invisible Higgs Boson

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    We consider a simple extension of the Standard Model by the addition of N real scalar gauge singlets \vp that are candidates for Dark Matter. By collecting theoretical and experimental constraints we determine the space of allowed parameters of the model. The possibility of ameliorating the little hierarchy problem within the multi-singlet model is discussed. The Spergel-Steinhardt solution of the Dark Matter density cusp problem is revisited. It is shown that fitting the recent CRESST-II data for Dark Matter nucleus scattering implies that the standard Higgs boson decays predominantly into pairs of Dark Matter scalars. It that case discovery of the Higgs boson at LHC and Tevatron is impossible. The most likely mass of the dark scalars is in the range 15 GeV \lsim \mvp \lsim 50 GeV with BR(h \to \vp\vp) up to 96%.Comment: 18 pages, 15 figure

    Dark Matter from Minimal Flavor Violation

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    We consider theories of flavored dark matter, in which the dark matter particle is part of a multiplet transforming nontrivially under the flavor group of the Standard Model in a manner consistent with the principle of Minimal Flavor Violation (MFV). MFV automatically leads to the stability of the lightest state for a large number of flavor multiplets. If neutral, this particle is an excellent dark matter candidate. Furthermore, MFV implies specific patterns of mass splittings among the flavors of dark matter and governs the structure of the couplings between dark matter and ordinary particles, leading to a rich and predictive cosmology and phenomenology. We present an illustrative phenomenological study of an effective theory of a flavor SU(3)_Q triplet, gauge singlet scalar.Comment: 10 pages, 2 figures; v2: references added, minor changes to collider analysis, conclusions unchange

    Dysaesthesia in the mental nerve distribution triggered by a foreign body: a case report

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    INTRODUCTION: Foreign bodies' entrapments in the mandibular and submandibular regions are quite common. CASE PRESENTATION: We report an unusual case of foreign body (amalgam filling) entrapment over the mental foramen causing dysaesthesia in the distribution of the mental nerve. An interesting sign was blue discoloration of the overlaying oral mucosa which was interpreted as amalgam tattooing. CONCLUSION: Surgical removal of the foreign object eliminated the reported symptoms

    Exploring the Higgs Portal with 10/fb at the LHC

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    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

    Depression among women living in the outskirts of São Paulo, Southeastern Brasil

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    OBJECTIVE: To assess the meaning of depression in women diagnosed with the disorder, and the context of care given by the psychiatrists who follow them up. METHODS: Qualitative study performed in Embu, outskirt of São Paulo, between August 2002 and January 2003. Etnographic observation and in-depth interview were carried out with 16 women diagnosed with depression in primary care, and four psychiatrists. After exhaustive reading, data were grouped into categories and assessed. The assessment of outcomes was based on the concept of culture. RESULTS: Women interviewed are well aware of the disorder, and accept treatment based on medication. For psychiatrists, depression is a term understood by the common sense. All women interviewed identified the onset of the disease from a past event such as: death of a son, violent episodes connected with drug traffic, unemployment, and partners' aggressiveness. Violence was common in the every day life of the interviewed women both inside and outside their homes. CONCLUSIONS: For these women, depression is a way to express their feelings, such as unhappiness in a context of poverty and violence. Psychiatrists go beyond their clinical functions and play an important role on reorganizing the daily life of these women.OBJETIVO: Analisar o significado da depressão para mulheres diagnosticadas com o transtorno e o contexto do atendimento realizado pelos psiquiatras que as acompanham. MÉTODOS: Estudo qualitativo realizado no município de Embu, na Grande São Paulo, entre agosto de 2002 e janeiro de 2003. Foram realizadas observação etnográfica e entrevistas em profundidade com 16 mulheres diagnosticadas com depressão, pacientes de uma Unidade Básica de Saúde, e quatro psiquiatras. Após a leitura exaustiva, os dados foram agrupados em categorias e analisados. A interpretação dos resultados baseou-se no conceito de cultura. RESULTADOS: As entrevistadas tinham ampla noção do transtorno, aceitando o tratamento com medicação. Para os psiquiatras, a depressão é um termo assimilado pelo senso-comum. Todas as entrevistadas identificaram a origem da doença em eventos passados, como: morte de filho, episódios violentos ligados ao tráfico de drogas, desemprego e agressividade do companheiro. A violência era comum no cotidiano das entrevistadas, tanto fora como dentro de casa. CONCLUSÕES: Para essas mulheres, a depressão era uma forma de expressar sentimentos, como a infelicidade num contexto de pobreza e violência. Os psiquiatras extrapolam as suas funções clínicas e têm um papel na reorganização do cotidiano dessas mulheres.Universidade Católica de Santos Programa de Mestrado em Saúde ColetivaUniversidade Federal de São Paulo (UNIFESP) Departamento de PsiquiatriaUNIFESP, Depto. de PsiquiatriaSciEL

    Genome of the Avirulent Human-Infective Trypanosome—Trypanosoma rangeli

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    Background: Trypanosoma rangeli is a hemoflagellate protozoan parasite infecting humans and other wild and domestic mammals across Central and South America. It does not cause human disease, but it can be mistaken for the etiologic agent of Chagas disease, Trypanosoma cruzi. We have sequenced the T. rangeli genome to provide new tools for elucidating the distinct and intriguing biology of this species and the key pathways related to interaction with its arthropod and mammalian hosts.  Methodology/Principal Findings: The T. rangeli haploid genome is ,24 Mb in length, and is the smallest and least repetitive trypanosomatid genome sequenced thus far. This parasite genome has shorter subtelomeric sequences compared to those of T. cruzi and T. brucei; displays intraspecific karyotype variability and lacks minichromosomes. Of the predicted 7,613 protein coding sequences, functional annotations could be determined for 2,415, while 5,043 are hypothetical proteins, some with evidence of protein expression. 7,101 genes (93%) are shared with other trypanosomatids that infect humans. An ortholog of the dcl2 gene involved in the T. brucei RNAi pathway was found in T. rangeli, but the RNAi machinery is non-functional since the other genes in this pathway are pseudogenized. T. rangeli is highly susceptible to oxidative stress, a phenotype that may be explained by a smaller number of anti-oxidant defense enzymes and heatshock proteins.  Conclusions/Significance: Phylogenetic comparison of nuclear and mitochondrial genes indicates that T. rangeli and T. cruzi are equidistant from T. brucei. In addition to revealing new aspects of trypanosome co-evolution within the vertebrate and invertebrate hosts, comparative genomic analysis with pathogenic trypanosomatids provides valuable new information that can be further explored with the aim of developing better diagnostic tools and/or therapeutic targets

    Dynamical Boson Stars

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    The idea of stable, localized bundles of energy has strong appeal as a model for particles. In the 1950s John Wheeler envisioned such bundles as smooth configurations of electromagnetic energy that he called {\em geons}, but none were found. Instead, particle-like solutions were found in the late 1960s with the addition of a scalar field, and these were given the name {\em boson stars}. Since then, boson stars find use in a wide variety of models as sources of dark matter, as black hole mimickers, in simple models of binary systems, and as a tool in finding black holes in higher dimensions with only a single killing vector. We discuss important varieties of boson stars, their dynamic properties, and some of their uses, concentrating on recent efforts.Comment: 79 pages, 25 figures, invited review for Living Reviews in Relativity; major revision in 201
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