230 research outputs found

    Measurement and interpretation of same-sign W boson pair production in association with two jets in pp collisions at s = 13 TeV with the ATLAS detector

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    This paper presents the measurement of fducial and diferential cross sections for both the inclusive and electroweak production of a same-sign W-boson pair in association with two jets (W±W±jj) using 139 fb−1 of proton-proton collision data recorded at a centre-of-mass energy of √s = 13 TeV by the ATLAS detector at the Large Hadron Collider. The analysis is performed by selecting two same-charge leptons, electron or muon, and at least two jets with large invariant mass and a large rapidity diference. The measured fducial cross sections for electroweak and inclusive W±W±jj production are 2.92 ± 0.22 (stat.) ± 0.19 (syst.)fb and 3.38±0.22 (stat.)±0.19 (syst.)fb, respectively, in agreement with Standard Model predictions. The measurements are used to constrain anomalous quartic gauge couplings by extracting 95% confdence level intervals on dimension-8 operators. A search for doubly charged Higgs bosons H±± that are produced in vector-boson fusion processes and decay into a same-sign W boson pair is performed. The largest deviation from the Standard Model occurs for an H±± mass near 450 GeV, with a global signifcance of 2.5 standard deviations

    Combination of searches for heavy spin-1 resonances using 139 fb−1 of proton-proton collision data at s = 13 TeV with the ATLAS detector

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    A combination of searches for new heavy spin-1 resonances decaying into different pairings of W, Z, or Higgs bosons, as well as directly into leptons or quarks, is presented. The data sample used corresponds to 139 fb−1 of proton-proton collisions at = 13 TeV collected during 2015–2018 with the ATLAS detector at the CERN Large Hadron Collider. Analyses selecting quark pairs (qq, bb, , and tb) or third-generation leptons (τν and ττ) are included in this kind of combination for the first time. A simplified model predicting a spin-1 heavy vector-boson triplet is used. Cross-section limits are set at the 95% confidence level and are compared with predictions for the benchmark model. These limits are also expressed in terms of constraints on couplings of the heavy vector-boson triplet to quarks, leptons, and the Higgs boson. The complementarity of the various analyses increases the sensitivity to new physics, and the resulting constraints are stronger than those from any individual analysis considered. The data exclude a heavy vector-boson triplet with mass below 5.8 TeV in a weakly coupled scenario, below 4.4 TeV in a strongly coupled scenario, and up to 1.5 TeV in the case of production via vector-boson fusion

    Corrigendum to "Search for flavour-changing neutral-current couplings between the top quark and the photon with the ATLAS detector at √s=13 TeV" (Physics Letters B, 842 (2023), 137379)

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    Search for neutral long-lived particles in pp collisions at s√ = 13 TeV that decay into displaced hadronic jets in the ATLAS calorimeter

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    A search for decays of pair-produced neutral long-lived particles (LLPs) is presented using 139 fb−1 of proton-proton collision data collected by the ATLAS detector at the LHC in 2015–2018 at a centre-of-mass energy of 13 TeV. Dedicated techniques were developed for the reconstruction of displaced jets produced by LLPs decaying hadronically in the ATLAS hadronic calorimeter. Two search regions are defined for different LLP kinematic regimes. The observed numbers of events are consistent with the expected background, and limits for several benchmark signals are determined. For a SM Higgs boson with a mass of 125 GeV, branching ratios above 10% are excluded at 95% confidence level for values of c times LLP mean proper lifetime in the range between 20 mm and 10 m depending on the model. Upper limits are also set on the cross-section times branching ratio for scalars with a mass of 60 GeV and for masses between 200 GeV and 1 TeV

    Search for dark photons in rare Z boson decays with the ATLAS detector

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    A search for events with a dark photon produced in association with a dark Higgs boson via rare decays of the standard model Z boson is presented, using 139     fb − 1 of √ s = 13     TeV proton-proton collision data recorded by the ATLAS detector at the Large Hadron Collider. The dark boson decays into a pair of dark photons, and at least two of the three dark photons must each decay into a pair of electrons or muons, resulting in at least two same-flavor opposite-charge lepton pairs in the final state. The data are found to be consistent with the background prediction, and upper limits are set on the dark photon’s coupling to the dark Higgs boson times the kinetic mixing between the standard model photon and the dark photon, α D ϵ 2 , in the dark photon mass range of [5, 40] GeV except for the Υ mass window [8.8, 11.1] GeV. This search explores new parameter space not previously excluded by other experiments

    Combined measurement of the Higgs boson mass from the H → γγ and H → ZZ∗ → 4ℓ decay channels with the ATLAS detector using √s = 7, 8, and 13 TeV pp collision data

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    A measurement of the mass of the Higgs boson combining the H → Z Z ∗ → 4 ℓ and H → γ γ decay channels is presented. The result is based on 140     fb − 1 of proton-proton collision data collected by the ATLAS detector during LHC run 2 at a center-of-mass energy of 13 TeV combined with the run 1 ATLAS mass measurement, performed at center-of-mass energies of 7 and 8 TeV, yielding a Higgs boson mass of 125.11 ± 0.09 ( stat ) ± 0.06 ( syst ) = 125.11 ± 0.11     GeV . This corresponds to a 0.09% precision achieved on this fundamental parameter of the Standard Model of particle physics

    Congresso Brasileiro de Enfermagem: sessenta anos de história Congreso Brasileño de Enfermería: sesenta años de historia The Brazilian Nursing Congress: sixty years of history

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    Este estudo objetivou descrever as questões ligadas às origens do Congresso Brasileiro de Enfermagem e sua trajetória no período de 1947 a 2007; e discutir a implementação desta estratégia pela Associação Brasileira de Enfermagem (ABEn). É uma investigação histórica com pesquisa documental. A análise permitiu chegar as seguintes categorias: a origem do Congresso brasileiro de enfermagem e; os congressos como arena política da enfermagem. Concluímos que os Congressos Brasileiros de Enfermagem vêm refletindo a construção da história da Enfermagem brasileira, com vistas a impulsionar a reflexão crítica dos problemas da profissão e investir na produção de conhecimentos, direcionados para a crescente complexidade e qualidade da prática profissional.<br>Este estudio tiene como objetivos describir las cuestiones que se refieren a los orígenes del Congreso Brasileño de Enfermería y su trayectoria en el periodo de 1947 a 2007; y discutir si la Asociación Brasileña de Enfermería (ABEn) debe implantar esta estrategia. Es una investigación histórica con averiguación documental. El análisis documental permitió llegar a las siguientes categorías: el origen del Congreso Brasileño de Enfermería y; los congresos como arena política de la enfermería. Concluimos que los Congresos Brasileños de Enfermería están reflejando la construcción de la historia de la Enfermería brasileña, con el objetivo de impulsar la reflexión crítica de los problemas de la profesión e invertir en la producción de conocimientos, dirigidos a la creciente complejidad y calidad de la práctica profesional.<br>This study objective is to describe the issues associated to the origin of the Brazilian Nursing Congress and its course between 1947 and 2007; and to discuss the implementation of this strategy by the Brazilian Nursing Association (ABEn). It is a historical survey with documentary research. The documentary analysis allowed reaching the following categories: the origin of the Brazilian Nursing Congress and the congresses as the political nursing arena. We have concluded that the Brazilian Nursing Congresses have reflected the construction of the Brazilian Nursing history, aiming at stimulating the critical consideration on the professional problems and investing in the production of knowledge, addressing the growing complexity and quality of the professional practice

    Pimpinella alpina Molk Administration is Capable of Increasing Antioxidant and Decreasing Prooxidant Level following UVB Irradiation

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    Operations of and Future Plans for the Pierre Auger Observatory

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    Contributions to the 31st ICRC, Lodz, Poland, July 2009International audienceTechnical reports on operations and features of the Pierre Auger Observatory, including ongoing and planned enhancements and the status of the future northern hemisphere portion of the Observatory. Contributions to the 31st International Cosmic Ray Conference, Lodz, Poland, July 2009

    Studies of Cosmic Ray Composition and Air Shower Structure with the Pierre Auger Observatory

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    Submissions to the 31st International Cosmic Ray Conference, Lodz, Poland (July 2009)International audienceStudies of the composition of the highest energy cosmic rays with the Pierre Auger Observatory, including examination of hadronic physics effects on the structure of extensive air showers. Submissions to the 31st ICRC, Lodz, Poland (July 2009)
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