2,354 research outputs found

    The sit up test to exhaustion as a test for muscular endurance evaluation

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    AIMS/HYPOTHESIS The aim of this study was to examine the sit up test to exhaustion as a field test for muscular endurance evaluation in a sample of sedentary people of both sexes. METHODS: A cross-sectional study was performed. Three-hundred-eighty-one participants volunteered for the study (28.5 \ub1 10.0 years; 168.2 \ub1 8.9 cm; 65.1 \ub1 11.1 kg), of which 194 males (27.5 \ub1 10.2 years; 173.6 \ub1 7.0 cm; 71.2 \ub1 5.2 kg) and 187 females (29.6 \ub1 10.1 years; 162.6 \ub1 7.1 cm; 58.7 \ub1 8.9 kg). Each subject voluntarily and randomly performed: a sit up test (SUT), a push up test (PUT), and a free weight squat test (ST), all till exhaustion. A multiple regression analysis was adopted for data analysis. Subsequently a percentile model for muscle endurance was developed. The 25th, 50th, and 75th percentile were identified as upper limit for low muscular endurance, average muscular endurance, and lower limit for high muscular endurance, respectively. RESULTS: Considering the sit up test as the dependent variable, the coefficients (R(2) = 0.23; r = 0.49; p < 0.001), and (R(2) = 0.31; r = 0.57; p < 0.001) emerged from a multiple regression analysis applied with respect to the push up test and the squat test, respectively. Gender stratification showed regression coefficients of (R(2) = 0.19; r = 0.44; p < 0.001) for SUT vs. PUT, and (R(2) = 0.30; r = 0.56; p < 0.001) for SUT vs. ST in male; and (R(2) = 0.23; r = 0.49; p < 0.001) for SUT vs. PUT, and (R(2) = 0.34; r = 0.59; p < 0.001) for SUT vs. ST in female. CONCLUSIONS/INTERPRETATION: The SUT showed low inter-relation with the other proposed tests indicating that the adoption of a single test for the global evaluation of muscle endurance is not the optimal approach. Moreover, the SUT was found to be inexpensive, safe, and appropriate for core muscle endurance measurement for both male and female

    Search for direct chargino production in anomaly-mediated supersymmetry breaking models based on a disappearing-track signature in pp collisions at sqrt(s) = 7 TeV with the ATLAS detector

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    A search for direct chargino production in anomaly-mediated supersymmetry breaking scenarios is performed in pp collisions at sqrt(s) = 7 TeV using 4.7 fb−1 of data collected with the ATLAS experiment at the LHC. In these models, the lightest chargino is predicted to have a lifetime long enough to be detected in the tracking detectors of collider experiments. This analysis explores such models by searching for chargino decays that result in tracks with few associated hits in the outer region of the tracking system. The transverse-momentum spectrum of candidate tracks is found to be consistent with the expectation from the Standard Model background processes and constraints on chargino properties are obtained

    Searches for heavy long-lived sleptons and R-hadrons with the ATLAS detector in pp collisions at sqrt(s) = 7 TeV

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    A search for long-lived particles is performed using a data sample of 4.7 fb−1 from proton–proton collisions at a centre-of-mass energy sqrt(s) = 7 TeV collected by the ATLAS detector at the LHC. No excess is observed above the estimated background and lower limits, at 95% confidence level, are set on the mass of the long-lived particles in different scenarios, based on their possible interactions in the inner detector, the calorimeters and the muon spectrometer. Long-lived staus in gauge-mediated SUSY-breaking models are excluded up to a mass of 300 GeV for tanbeta 5-20. Directly produced long-lived sleptons are excluded up to a mass of 278 GeV. R-hadrons, composites of gluino (stop, sbottom) and light quarks, are excluded up to a mass of 985 GeV (683 GeV, 612 GeV) when using a generic interaction model. Additionally two sets of limits on R-hadrons are obtained that are less sensitive to the interaction model for R-hadrons. One set of limits is obtained using only the inner detector and calorimeter observables, and a second set of limits is obtained based on the inner detector alone

    Search for the neutral Higgs bosons of the Minimal Supersymmetric Standard Model in pp collisions at sqrt(s) = 7 TeV with the ATLAS detector

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    A search for neutral Higgs bosons of the Minimal Supersymmetric Standard Model (MSSM) is reported. The analysis is based on a sample of proton-proton collisions at a centre-of-mass energy of 7 TeV recorded with the ATLAS detector at the Large Hadron Collider. The data were recorded in 2011 and correspond to an integrated luminosity of 4.7 fb−1 to 4.8 fb−1. Higgs boson decays into oppositely-charged muon or τ lepton pairs are considered for final states requiring either the presence or absence of b-jets. No statistically significant excess over the expected background is observed and exclusion limits at the 95% confidence level are derived. The exclusion limits are for the production cross-section of a generic neutral Higgs boson, φ, as a function of the Higgs boson mass and for h/A/H production in the MSSM as a function of the parameters m A and tan β in the mmaxh scenario for m A in the range of 90 GeV to 500 GeV

    Measurement of the inclusive and dijet cross-sections of b-jets in pp collisions at sqrt(s) = 7 TeV with the ATLAS detector

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    The inclusive and dijet production cross-sections have been measured for jets containing b-hadrons (b-jets) in proton-proton collisions at a centre-of-mass energy of sqrt(s) = 7 TeV, using the ATLAS detector at the LHC. The measurements use data corresponding to an integrated luminosity of 34 pb^-1. The b-jets are identified using either a lifetime-based method, where secondary decay vertices of b-hadrons in jets are reconstructed using information from the tracking detectors, or a muon-based method where the presence of a muon is used to identify semileptonic decays of b-hadrons inside jets. The inclusive b-jet cross-section is measured as a function of transverse momentum in the range 20 < pT < 400 GeV and rapidity in the range |y| < 2.1. The bbbar-dijet cross-section is measured as a function of the dijet invariant mass in the range 110 < m_jj < 760 GeV, the azimuthal angle difference between the two jets and the angular variable chi in two dijet mass regions. The results are compared with next-to-leading-order QCD predictions. Good agreement is observed between the measured cross-sections and the predictions obtained using POWHEG + Pythia. MC@NLO + Herwig shows good agreement with the measured bbbar-dijet cross-section. However, it does not reproduce the measured inclusive cross-section well, particularly for central b-jets with large transverse momenta

    Search for Diphoton Events with Large Missing Transverse Momentum in 1 fb-1 of 7 TeV Proton-Proton Collision Data with the ATLAS Detector

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    A search for diphoton events with large missing transverse momentum has been performed using 1.07 fb^-1 of proton-proton collision data at sqrt(s) = 7 TeV recorded with the ATLAS detector. No excess of events was observed above the Standard Model prediction and 95% Confidence Level (CL) upper limits are set on the production cross section for new physics: sigma < (22-129) fb in the context of a generalised model of gauge-mediated supersymmetry breaking (GGM) with a bino-like lightest neutralino, sigma < (27-91) fb in the context of a minimal model of gauge-mediated supersymmetry breaking (SPS8) and (15-27) fb in the context of a specific model with one universal extra dimension (UED). A 95% CL lower limit of 805 GeV, for bino masses above 50 GeV, is set on the GGM gluino mass. Lower limits of 145 TeV and 1.23 TeV are set on the SPS8 breaking scale Lambda and on the UED compactification scale 1/R, respectively. These limits provide the most stringent tests of these models to date

    Search for direct third generation squark pair production in final states with Missing Transverse Momentum and two b-jets in sqrt(s) = 8 TeV pp collisions with the ATLAS detector

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    The results of a search for pair production of supersymmetric partners of the Standard Model third-generation quarks are reported. This search uses 20.1 fb−1 of pp collisions at sqrt(s) = 8 TeV collected by the ATLAS experiment at the Large Hadron Collider. The lightest bottom and top squarks (˜b1 and ˜t1 respectively) are searched for in a final state with large missing transverse momentum and two jets identified as originating from b-quarks. No excess of events above the expected level of Standard Model background is found. The results are used to set upper limits on the visible cross section for processes beyond the Standard Model. Exclusion limits at the 95% confidence level on the masses of the third-generation squarks are derived in phenomenological supersymmetric R-parityconserving models in which either the bottom or the top squark is the lightest squark. The˜b1 is assumed to decay via ˜b1 ! b˜χ01 and the ˜t1 via ˜t1 -> b˜χ±1 , with undetectable products of the subsequent decay of the ˜χ±1 due to the small mass splitting between the ˜χ±1 and the ˜χ01

    Measurement of the WZ production cross section and limits on anomalous triple gauge couplings in proton-proton collisions at sqrt(s) = 7 TeV with the ATLAS detector

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    This Letter presents a measurement of WZ production in 1.02 fb^-1 of pp collision data at sqrt(s) = 7 TeV collected by the ATLAS experiment in 2011. Doubly leptonic decay events are selected with electrons, muons and missing transverse momentum in the final state. In total 71 candidates are observed, with a background expectation of 12.1 +/- 1.4(stat.) +4.1/-2.0(syst) events. The total cross section for WZ production for Z gamma^* masses within the range 66 GeV to 116 GeV is determined to be sigma_WZ^tot = 20.5 +3.1/-2.8(stat.) +1.4/-1.3(syst.) +0.9/-0.8(lumi.)pb, which is consistent with the Standard Model expectation of 17.3 +1.3/-0.8 pb. Limits on anomalous triple gauge boson couplings are extracted

    Search for first generation scalar leptoquarks in pp collisions at sqrt(s)=7 TeV with the ATLAS detector

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    We report a search for first generation scalar leptoquarks using 1.03 fb^-1 of proton-proton collisions data produced by the Large Hadron Collider at sqrt(s)=7 TeV and recorded by the ATLAS experiment. Leptoquarks are sought via their decay into an electron or neutrino and a quark, producing events with two oppositely charged electrons and at least two jets, or events with an electron, missing transverse momentum and at least two jets. Control data samples are used to validate background predictions from Monte Carlo simulation. In the signal region, the observed event yields are consistent with the background expectations. We exclude at 95% confidence level the production of first generation scalar leptoquark with masses m_LQ &lt; 660 (607) GeV when assuming the branching fraction of a leptoquark to a charged lepton is equal to 1.0 (0.5)

    Search for top and bottom squarks from gluino pair production in final states with missing transverse energy and at least three b-jets with the ATLAS detector

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    This letter reports the results of a search for top and bottom squarks from gluino pair production in 4.7 fb−1 of pp collisions at sqrt(s) = 7 TeV using the ATLAS detector at the LHC. The search is performed in events with large missing transverse momentum and at least three jets identified as originating from a b-quark. Exclusion limits are presented for a variety of gluino-mediated models with gluino masses up to 1 TeV excluded
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