Search for physics beyond the standard model in events with τ leptons, jets, and large transverse momentum imbalance in pp collisions at √s = 7 TeV

A search for physics beyond the standard model is performed with events having one or more hadronically decaying τ leptons, highly energetic jets, and large transverse momentum imbalance. The data sample corresponds to an integrated luminosity of 4.98 fb-1 of proton-proton collisions at √ = 7 TeV collected with the CMS detector at the LHC in 2011. The number of observed events is consistent with predictions for standard model processes. Lower limits on the mass of the gluino in supersymmetric models are determined. © 2013 CERN for the benefit of the CMS collaboration.

Uranium-lead dating method at the Pará-Iso isotope geology laboratory, UFPA, Belém – Brazil

ABSTRACT: Analytical procedures for U-Pb isotope dilution analyses at the Pará-Iso isotope geology laboratory of the Federal University of Pará (UFPA) are described in detail. The procedures are applied to zircon, titanite, rutile, apatite, columbite-tantalite and whole rock. Reagent preparation and chemical processing are done in clean-room conditions. Samples are dissolved using Teflon™ microcapsules in steel jacket Teflon™ Parr Instrument™ bomb or Teflon™ screw cap containers. U and Pb are separated using anion exchange AG 1x8 resin columns. Typical blanks for mineral sample amounts of 0.01 to 1.0 mg are less than 1 pg U and 20-30 pg Pb. Isotope analysis of the U and Pb from the same filament are carried out using a Finnigan MAT 262 mass-spectrometer in static and dynamic modes. The current analytical level is demonstrated on analyses of international standard zircon 91500 with three different ²³⁵U-²⁰⁵Pb and ²³⁵U-²⁰⁸Pb isotope tracers and whole rock standards. Results of analyses of two zircon samples are also presented.

Adequações tecnológicas no beneficiamento do caranguejo-uçá Ucides cordatus (Linnaeus, 1763) desenvolvido na comunidade de Caratateua, município de Bragança, estado do Pará, Brasil

No Estado do Pará, o beneficiamento do caranguejo-uçá ocorre de forma totalmente artesanal, sendo o seu produto frequentemente associado a eventos de intoxicação alimentar. Neste trabalho o autor tem por finalidade propor adequações tecnológicas no processamento deste crustáceo desenvolvido na comunidade de Caratateua, município de Bragança/Pará. Foram realizadas excurs��es mensais à comunidade de abril/2008 a maio/2009 com aplicação de 120 entrevistas direcionadas aos principais atores sociais envolvidos na atividade, constando de aspectos econômicos, sociais e tecnológicos, além de análises laboratoriais (composição química e microbiologia), observações de campo e revisão de literatura. Constatou-se que a quantidade de caranguejo desembarcada e o tamanho médio dos indivíduos vêm diminuindo nos últimos anos. A captura é realizada exclusivamente por indivíduos do sexo masculino, sendo o gancho o principal apetrecho utilizado. O beneficiamento é praticado principalmente por mulheres e crianças, porém homens eventualmente também o fazem. Não há uma padronização do processamento e as condições higiênico-sanitárias dos locais de beneficiamento são na grande maioria das vezes inadequadas, podendo este ser realizado no interior da residência, em “puxadinhas” ou nos quintais, geralmente na presença de animais domésticos, insetos e sem a adequada assepsia de manipuladores, equipamentos e superfícies de contato. Desta forma, conclui-se que tal realidade é ocasionada principalmente pelo desordenamento da pescaria e falta de preocupação dos catadores quanto à qualidade do produto, sendo de fundamental importância a criação de uma legislação específica para a carne de caranguejo e a adoção de boas práticas de fabricação levando em consideração a realidade local visando agregação de valor ao produto e maior segurança alimentar aos consumidores.

Searches for new physics using the t(t)over-bar invariant mass distribution in pp collisions at root s=8 TeV

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Search for new physics in events with same-sign dileptons and jets in pp collisions at root s=8 TeV

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Search for new physics in the multijet and missing transverse momentum final state in proton-proton collisions at root s=8 Tev

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Comparison of Nonmesonic Hypernuclear Decay Rates Computed in Laboratory and Center-of-Mass Coordinates

In this work we compute the one-nucleon-induced nonmesonic hypernuclear decay rates of He-5(Lambda), C-12(Lambda) and C-13(Lambda) using a formalism based on the independent particle shell model in terms of laboratory coordinates. To ascertain the correctness and precision of the method, these results are compared with those obtained using a formalism in terms of center-of-mass coordinates, which has been previously reported in the literature. The formalism in terms of laboratory coordinates will be useful in the shell-model approach to two-nucleon-induced transitions.

Interactive simulations to physics teaching: a case study in brazilian high school

This paper presents the results of a study that investigated the use of simulators to improve physics teaching. The study population consisted of eight classes totaling 205 second year high school students from Brazilian public school. The research methodology adopted compares the average performance of students on tests conducted in the classroom to performance on tests conducted in the laboratory using computer simulators. The results obtained showed that students’ performance on tests improved after the use of simulators. It was found that the students had more homogeneous test results when using the simulator.

Study of vector boson scattering and search for new physics in events with two same-sign leptons and two jets

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Search for physics beyond the standard model in final states with a lepton and missing transverse energy in proton-proton collisions at root s = 8 TeV

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Search for physics beyond the standard model in dilepton mass spectra in proton-proton collisions at root s=8 TeV

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Search for physics beyond the standard model in events with two leptons, jets, and missing transverse momentum in pp collisions at root s=8 TeV

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

The electromagnetic gauge invariance in SU(3)L ⊗ U(1)N models of electroweak unification reexamined

Two models with SU(3)C ⊗ SU(3)L U(1)N gauge symmetry are considered. We show that the masslessness of the photon does not prevent the neutrinos from acquiring Majorana masses. That is, there is no relation between the VEVs of Higgs fields and the electromagnetic gauge invariance contrary to what has been claimed recently. © 1998 Elsevier Science B.V. All rights reserved.

On the evaluation of the U(3) content of the matrix elements of one- and two-body operators

An expression for the U(3) content of the matrix elements of one- and two-body operators in Elliott's basis is obtained. Three alternative ways of evaluating this content with increasing performance in computing time are presented. All of them allow an exact representation of that content in terms of integers, avoiding Founding errors in the computer codes. The role of dual bases in dealing with nonorthogonal bases is also clarified. © 1992 American Institute of Physics.

Clinical and laboratory characteristics of pregnant women with preeclampsia versus gestational hypertension

To compare clinical and laboratory characteristics, obstetric and perinatal outcomes of patients with pre-eclampsia versus gestational hypertension. A retrospective study was carried out to analyze medical records of patients diagnosed with pre-eclampsia and gestational hypertension whose pregnancies were resolved within a period of 5 years, for a total of 419 cases. We collected clinical and laboratory data, obstetric and perinatal outcomes. Comparisons between groups were performed using the test suitable for the variable analyzed: unpaired t test, Mann-Whitney U test or χ2 test, with the level of significance set at p<0.05. Were evaluated 199 patients in the gestational hypertension group (GH) and 220 patients in the pre-eclampsia group (PE). Mean body mass index was 34.6 kg/m2 in the GH group and 32.7 kg/m2 in the PE group, with a significant difference between groups. The PE group showed higher systolic and diastolic blood pressure and higher rates of abnormal values in the laboratory tests, although the mean values were within the normal range. Cesarean section was performed in 59.1% of cases of PE and in 47.5% of the GH group; and perinatal outcomes in terms of gestational age and birth weight were significantly lower in the PE group. Women with gestational hypertension exhibit epidemiological characteristics of patients at risk for chronic diseases. Patients with pre-eclampsia present clinical and laboratory parameters of greater severity, higher rates of cesarean delivery and worse maternal and perinatal outcomes.