2,094 research outputs found

    O ACESSO DO ESTUDANTE COM DEFICIÊNCIA VISUAL À EDUCAÇÃO SUPERIOR: ANÁLISE DOS MICRODADOS DO EXAME NACIONAL DO ENSINO MÉDIO (ENEM)

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    The Brazilian National High School Examination (Exame Nacional do Ensino Médio – ENEM) is the main instrument of access to the Brazilian Higher Education, and its results are also used by public policies for state-subsidized places. Thus, the aim of this study was to analyze the access to Higher Education of students with visual impairments, investigating factors related to academic performance in the large-scale assessment of ENEM, through the analysis of ENEM microdata from the 2017 and 2018 editions. Based on the exploratory research methodology, with a quantitative approach, this study investigated the participation, socioeconomic and demographic characteristics and the performance of people with visual impairments (PwVi) in the exam compared to participants without disabilities, in order to identify vulnerabilities in the access of PwVi to Higher Education. The results showed the low participation of PwVi in the exam, in addition to the fact that they have lower family income, older age, less female participation and less concentration in the South and Southeast regions of Brazil in relation to participants without disabilities. The performance analysis points out that PwVi had similar results to people without disabilities, thus demystifying the concept of disability related to people with disability. However, the results varied according to the severity of the disability, signaling possible accessibility issues in the exam, thus jeopardizing participants with more severe visual impairment. It was concluded that the education policies of access to Higher Education, which use the ENEM score, do not apply to part of this population, excluded from the benefits of Higher Education subsidized by the State.El Examen Nacional de la Enseñanza Secundaria (ENEM) es el principal instrumento de acceso a la Educación Superior brasileña, siendo sus resultados también utilizados por políticas públicas para ofertas de vacantes subsidiadas por el Estado. Así siendo, el objetivo, en este estudio, fue analizar el acceso a la Educación Superior del estudiante con discapacidad visual investigando factores relacionados con el rendimiento académico en la evaluación a gran escala de ENEM, por medio del análisis de microdatos del ENEM de las ediciones 2017 y 2018. Con base en la metodología de investigación exploratoria con enfoque cuantitativo, el presente estudio investigó la participación, las características socioeconómicas y demográficas y el desempeño de personas con discapacidad visual (PcDv) en el examen en comparación con las personas sin discapacidad (PsD), con el fin de identificar vulnerabilidades en el acceso de las PcDv a la Educación Superior. Los resultados mostraron baja participación de las PcDv en el examen, además de que estos poseen menor renta familiar, edad más avanzada, menor participación del sexo femenino y menor concentración en las regiones Sur y Sureste, en relación a las PcDv. El análisis de desempeño señala que las PcDv tuvieron resultados similares a las personas sin discapacidad, desmitificando así el concepto de incapacidad relacionado con las personas con discapacidad. Sin embargo, los resultados varían según la gravedad de la discapacidad, señalando posibles problemas de accesibilidad en el examen, perjudicando, de ese modo, a las personas con discapacidad visual más severa. Se concluyó que las políticas educativas de acceso a la Educación Superior, que utilizan la puntuación del ENEM, no se aplican a parte de esta población, excluida de los beneficios de la Educación Superior subsidiada por el Estado.O Exame Nacional do Ensino Médio (ENEM) é o principal instrumento de acesso à Educação Superior brasileira, sendo seus resultados também utilizados por políticas públicas para ofertas de vagas subsidiadas pelo Estado. Assim sendo, objetivou-se, neste estudo, analisar o acesso à Educação Superior da pessoa com deficiência visual (PcDv) investigando fatores relacionados aos rendimentos acadêmicos na avaliação em larga escala do ENEM, por meio da análise de microdados das edições de 2017 e 2018 do exame. Com base na metodologia de pesquisa exploratória, com abordagem quantitativa, este estudo investigou a participação, as características socioeconômicas e demográficas e o desempenho das PcDv no exame em comparação aos participantes sem deficiência, com a finalidade de identificar vulnerabilidades no acesso das PcDv à Educação Superior. Os resultados evidenciaram a baixa participação de PcDv no exame, além de estes possuírem menor renda familiar, idade mais avançada, menor participação do sexo feminino e menor concentração nas regiões Sul e Sudeste em relação aos participantes sem deficiência. A análise de desempenho aponta que as PcDv tiveram resultados similares às pessoas sem deficiência, desmistificando, assim, o conceito de incapacidade relacionado à pessoa com deficiência. No entanto,  os resultados variaram conforme a severidade da deficiência, sinalizando possíveis questões de acessibilidade no exame, prejudicando, desse modo, os participantes com deficiência visual mais severa. Concluiu-se que as políticas educacionais de acesso à Educação Superior, que utilizam a nota do ENEM, não se aplicam à parte dessa população, excluída dos benefícios da Educação Superior subsidiada pelo Estado

    Measurement of double-parton scattering in inclusive production of four jets with low transverse momentum in proton-proton collisions at s \sqrt{s} = 13 TeV

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    A measurement of inclusive four-jet production in proton-proton collisions at a center-of-mass energy of 13 TeV is presented. The transverse momenta of jets within |η| < 4.7 are required to exceed 35, 30, 25, and 20 GeV for the first-, second-, third-, and fourth-leading jet, respectively. Differential cross sections are measured as functions of the jet transverse momentum, jet pseudorapidity, and several other observables that describe the angular correlations between the jets. The measured distributions show sensitivity to different aspects of the underlying event, parton shower modeling, and matrix element calculations. In particular, the interplay between angular correlations caused by parton shower and double-parton scattering contributions is shown to be important. The double-parton scattering contribution is extracted by means of a template fit to the data, using distributions for single-parton scattering obtained from Monte Carlo event generators and a double-parton scattering distribution constructed from inclusive single-jet events in data. The effective double-parton scattering cross section is calculated and discussed in view of previous measurements and of its dependence on the models used to describe the single- parton scattering background

    Measurements of the pp → W±^{±}γγ and pp → Zγγ cross sections at s\sqrt{s} = 13 TeV and limits on anomalous quartic gauge couplings

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    The cross section for W or Z boson production in association with two photons is measured in proton-proton collisions at a centre-of-mass energy of 13 TeV. The data set corresponds to an integrated luminosity of 137 fb1^{-1} collected by the CMS experiment at the LHC. The W → ℓν and Z → ℓℓ decay modes (where ℓ = e, μ) are used to extract the Wγγ and Zγγ cross sections in a phase space defined by electron (muon) with transverse momentum larger than 30 GeV and photon transverse momentum larger than 20 GeV. All leptons and photons are required to have absolute pseudorapidity smaller than 2.5. The measured cross sections in this phase space are σ(Wγγ) = 13.6+1.9^{+1.9}1.9_{−1.9}(stat)+4.0^{+4.0}4.0_{−4.0}(syst) ± 0.08 (PDF + scale) fb and σ(Zγγ) = 5.41+0.58^{+0.58}0.55_{−0.55}(stat)+0.64^{+0.64}.070_{−.070}(syst) ± 0.06 (PDF + scale) fb. Limits on anomalous quartic gauge couplings are set in the framework of an effective field theory with dimension-8 operators

    Measurement of the Z boson differential production cross section using its invisible decay mode (Z -> nu(nu)over-bar) in proton-proton collisions at root s=13 TeV

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    Measurements of the total and differential fiducial cross sections for the Z boson decaying into two neutrinos are presented at the LHC in proton-proton collisions at a center-of-mass energy of 13TeV. The data were collected by the CMS detector in 2016 and correspond to an integrated luminosity of 35.9 fb(-1). In these measurements, events are selected containing an imbalance in transverse momentum and one or more energetic jets. The fiducial differential cross section is measured as a function of the Z boson transverse momentum. The results are combined with a previous measurement of charged-lepton decays of the Z boson. The measured total fiducial cross section for events with Z boson transverse momentum greater than 200 GeV is 3000(-170)(+180) fb.Peer reviewe

    Search for new particles in events with energetic jets and large missing transverse momentum in proton-proton collisions at root s=13 TeV

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    A search is presented for new particles produced at the LHC in proton-proton collisions at root s = 13 TeV, using events with energetic jets and large missing transverse momentum. The analysis is based on a data sample corresponding to an integrated luminosity of 101 fb(-1), collected in 2017-2018 with the CMS detector. Machine learning techniques are used to define separate categories for events with narrow jets from initial-state radiation and events with large-radius jets consistent with a hadronic decay of a W or Z boson. A statistical combination is made with an earlier search based on a data sample of 36 fb(-1), collected in 2016. No significant excess of events is observed with respect to the standard model background expectation determined from control samples in data. The results are interpreted in terms of limits on the branching fraction of an invisible decay of the Higgs boson, as well as constraints on simplified models of dark matter, on first-generation scalar leptoquarks decaying to quarks and neutrinos, and on models with large extra dimensions. Several of the new limits, specifically for spin-1 dark matter mediators, pseudoscalar mediators, colored mediators, and leptoquarks, are the most restrictive to date.Peer reviewe

    Inclusive nonresonant multilepton probes of new phenomena at s\sqrt{s}= 13 TeV

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    An inclusive search for nonresonant signatures of beyond the standard model (SM) phenomena in events with three or more charged leptons, including hadronically decaying τ leptons, is presented. The analysis is based on a data sample corresponding to an integrated luminosity of 138 fb1^{-1} of proton-proton collisions at s\sqrt{s}= 13 TeV collected by the CMS experiment at the LHC in 2016–2018. Events are categorized based on the lepton and b-tagged jet multiplicities and various kinematic variables. Three scenarios of physics beyond the SM are probed, and signal-specific boosted decision trees are used for enhancing sensitivity. No significant deviations from the background expectations are observed. Lower limits are set at 95% confidence level on the mass of type-III seesaw heavy fermions in the range 845–1065 GeV for various decay branching fraction combinations to SM leptons. Doublet and singlet vectorlike τ lepton extensions of the SM are excluded for masses below 1045 GeV and in the mass range 125–150 GeV, respectively. Scalar leptoquarks decaying exclusively to a top quark and a lepton are excluded below 1.12–1.42 TeV, depending on the lepton flavor. For the type-III seesaw as well as the vectorlike doublet model, these constraints are the most stringent to date. For the vectorlike singlet model, these are the first constraints from the LHC experiments. Detailed results are also presented to facilitate alternative theoretical interpretations

    Search for high-mass resonances decaying to a jet and a Lorentz-boosted resonance in proton-proton collisions at √s = 13 TeV

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    A search is reported for high-mass hadronic resonances that decay to a parton and a Lorentz-boosted resonance, which in turn decays into a pair of partons. The search is based on data collected with the CMS detector at the LHC in proton-proton collisions at , corresponding to an integrated luminosity of 138. The boosted resonance is reconstructed as a single wide jet with substructure consistent with a two-body decay. The high-mass resonance is thus considered as a dijet system. The jet substructure information and the kinematic properties of cascade resonance decays are exploited to disentangle the signal from the large quantum chromodynamics multijet background. The dijet mass spectrum is analyzed for the presence of new high-mass resonances, and is found to be consistent with the standard model background predictions. Results are interpreted in a warped extra dimension model where the high-mass resonance is a Kaluza–Klein gluon, the boosted resonance is a radion, and the final state partons are all gluons. Limits on the production cross section are set as a function of the Kaluza–Klein gluon and radion masses. These limits exclude at 95% confidence level models with Kaluza–Klein gluon masses in the range 2.0 to 4.3 TeV and radion masses in the range 0.20 to 0.74 TeV. By exploring a novel experimental signature, the observed limits on the Kaluza–Klein gluon mass are extended by up to about 1 TeV compared to previous searches

    MUSiC : a model-unspecific search for new physics in proton-proton collisions at root s=13TeV

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    Results of the Model Unspecific Search in CMS (MUSiC), using proton-proton collision data recorded at the LHC at a centre-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 35.9 fb(-1), are presented. The MUSiC analysis searches for anomalies that could be signatures of physics beyond the standard model. The analysis is based on the comparison of observed data with the standard model prediction, as determined from simulation, in several hundred final states and multiple kinematic distributions. Events containing at least one electron or muon are classified based on their final state topology, and an automated search algorithm surveys the observed data for deviations from the prediction. The sensitivity of the search is validated using multiple methods. No significant deviations from the predictions have been observed. For a wide range of final state topologies, agreement is found between the data and the standard model simulation. This analysis complements dedicated search analyses by significantly expanding the range of final states covered using a model independent approach with the largest data set to date to probe phase space regions beyond the reach of previous general searches.Peer reviewe

    Measurement of inclusive and differential cross sections for single top quark production in association with a W boson in proton-proton collisions at s \sqrt{s} = 13 TeV

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    Measurements of the inclusive and normalised differential cross sections are presented for the production of single top quarks in association with a W boson in proton-proton collisions at a centre-of-mass energy of 13 TeV. The data used were recorded with the CMS detector at the LHC during 2016-2018, and correspond to an integrated luminosity of 138 fb1^{−1}. Events containing one electron and one muon in the final state are analysed. For the inclusive measurement, a multivariate discriminant, exploiting the kinematic properties of the events is used to separate the signal from the dominant ttˉt\bar{t} background. A cross section of 79.2 ± 0.9 (stat) 8.0+7.7^{+7.7}_{−8.0} (syst) ± 1.2 (lumi) pb is obtained, consistent with the predictions of the standard model. For the differential measurements, a fiducial region is defined according to the detector acceptance, and the requirement of exactly one jet coming from the fragmentation of a bottom quark. The resulting distributions are unfolded to particle level and agree with the predictions at next-to-leading order in perturbative quantum chromodynamics

    Search for long-lived particles decaying to a pair of muons in proton-proton collisions at s \sqrt{s} = 13 TeV

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    An inclusive search for long-lived exotic particles decaying to a pair of muons is presented. The search uses data collected by the CMS experiment at the CERN LHC in proton-proton collisions at s√ = 13 TeV in 2016 and 2018 and corresponding to an integrated luminosity of 97.6 fb−1. The experimental signature is a pair of oppositely charged muons originating from a common secondary vertex spatially separated from the pp interaction point by distances ranging from several hundred μm to several meters. The results are interpreted in the frameworks of the hidden Abelian Higgs model, in which the Higgs boson decays to a pair of long-lived dark photons ZD, and of a simplified model, in which long-lived particles are produced in decays of an exotic heavy neutral scalar boson. For the hidden Abelian Higgs model with m(ZD) greater than 20 GeV and less than half the mass of the Higgs boson, they provide the best limits to date on the branching fraction of the Higgs boson to dark photons for cτ(ZD) (varying with m(ZD)) between 0.03 and ≈0.5 mm, and above ≈0.5 m. Our results also yield the best constraints on long-lived particles with masses larger than 10 GeV produced in decays of an exotic scalar boson heavier than the Higgs boson and decaying to a pair of muons
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