289 research outputs found

    Early physics with top quarks at the LHC

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    The ATLAS and CMS experiments are now in their final installation phase and will be soon ready to study the physics of proton-proton collisions at the Large Hadron Collider. The LHC, by producing 2 ttˉt\bar{t} events per second, will provide more than 8 million top events a year at start-up. In this paper, particular emphasis is given to the ttˉt\bar{t} physics studies that can be performed at the beginning of the LHC running, with a limited amount of integrated luminosity (≀\le10 fb−1^{-1}).Comment: Proceedings of Moriond QCD 2007. Luminosity contribution to error on top pair production cross-section has been changed from 0.5% to 5.0

    Tracking and vertexing at ATLAS

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    Several algorithms for tracking and for primary and secondary vertex reconstruction have been developed by the ATLAS collaboration following different approaches. This has allowed a thorough cross-check of the performances of the algorithms and of the reconstruction software. The results of the most recent studies on this topic are discussed and compared.Comment: Proceedings of the HCP 2006 conferenc

    Searches for the Higgs boson in Minimal Supersymmetric CP-conserving and CP-violating Standard Model scenarios at LEP

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    It is important to study extended models containing more than one physical Higgs boson in the spectrum. In particular, Two Higgs Doublet Models (2HDMs) are attractive extensions of the SM, predicting new phenomena with the fewest new parameters. The Higgs sector in the Minimal Supersymmetric extension of the SM (MSSM) is a 2HDM itself. The neutral Higgs searches performed at LEP are showing no evidence of the presence of a signal and have therefore been interpreted in the context of 2HDMs. Depending on the model considered exclusion of large regions of the parameter space can be obtained, but the existence of the lightest Higgs boson with masses lower than 90 GeV is not ruled out in all models by LEP. In the MSSM at least one of the neutral Higgs bosons is predicted to have its mass close to the electroweak energy scale; when radiative corrections are included, this mass should be less than about 140 GeV. This prediction provides a strong motivation for searches at present and future colliders.Comment: 4 pages, 4 figure

    A Study of e+e- -> H0A0 -> bbbb at 3 TeV at CLIC

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    The precise determination of the masses of the CP-odd and -even heavy Higgs bosons is an important part of the study of Supersymmetry and its relation with cosmology through dark matter. This note presents a determination of the A0 boson mass with the e+e- -> H0A0 -> b b b b process for a dark matter motivated cMSSM scenario with M(A) = 1141 GeV at CLIC. The analysis is performed with full simulation and reconstruction at 3 TeV accounting for beamstrahlung effects. SM and SUSY backgrounds are considered and the effect of the overlay of gamma gamma -> hadrons events on the signal is studied for various assumptions for the detector time-stamping capabilities. The di-jet mass resolution is improved by applying a kinematic fit. The A0 mass can be determined with a statistical accuracy of ~3-5 GeV for 3 inverse ab of statistics and 0 to 20 bunch crossings of gamma gamma background integrated in one event, respectively.Comment: 11 pages, 4 figure

    Early physics with top quarks at LHC

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    The ATLAS and CMS experiments are now in their final installation phase and will be soon ready to study the physics of proton-proton collisions at the Large Hadron Collider. The LHC, by producing 2 t\bar{t} events per second, will provide more than 8 million top events a year at start-up. In this paper, particular emphasis is given to the t\bar{t} physics studies that can be performed at the beginning of the LHC running, with a limited amount of integrated luminosity ( <=10 fb-1)

    Imaging in pulmonary hypertension: Focus on the role of echocardiography

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    SummaryPatients with pulmonary hypertension must be evaluated using a multimodality approach to ensure a correct diagnosis and basal evaluation as well as a prognostic assessment. Beyond the assessment of pulmonary pressures, the echocardiographical examination allows the evaluation of right ventricular adaptation to elevated afterload. Numbers of variables are commonly used in the assessment of the pulmonary hypertension patient in order to detect changes in right heart geometry, right-to-left interaction and right ventricular dysfunction. Whereas an isolated change in one echocardiographical variable is not meaningful, multiple echocardiographical variable modifications together provide accurate information. In this review, we will link pulmonary hypertension pathophysiological changes with echocardiographical indices and describe the clinical implications of echocardiographical findings

    The effect of Public Health/Pediatric Obesity interventions on socioeconomic inequalities in childhood obesity: A scoping review

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    Childhood obesity has a strong social gradient. This scoping review aims to synthesize the evidence on the impact on inequalities of non-targeted interventions to reduce the prevalence of childhood and adolescent obesity in high-income countries. We updated a review by Hillier-Brown, searching up to 31 December 2017 on MEDLINE, Embase, The Cochrane Library, CINAHL, and PsycINFO, with no limitations on study design. Fifty-eight studies describing 51 interventions were included: 31 randomized clinical trials and 27 non-randomized trials, with sample sizes from 67 to 2,700,880 subjects. The majority were implemented in the school setting at a community level; the others were in health services or general population setting and targeting individuals or the system. Twenty-nine interventions proved to be effective overall; seven others had an effect only in a subgroup, while 15 proved not to be effective. All types of included interventions can increase inequalities. Moreover, some interventions had opposite effects based on the socioeconomic characteristics. Any kind of intervention can reduce equity. Consequences are difficult to predict based on intervention construct. Complex interventions acting on multiple targets, settings, and risk factors are more effective and have a lower risk of increasing inequalities
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