655 research outputs found

    Performance of the CMS Cathode Strip Chambers with Cosmic Rays

    Get PDF
    The Cathode Strip Chambers (CSCs) constitute the primary muon tracking device in the CMS endcaps. Their performance has been evaluated using data taken during a cosmic ray run in fall 2008. Measured noise levels are low, with the number of noisy channels well below 1%. Coordinate resolution was measured for all types of chambers, and fall in the range 47 microns to 243 microns. The efficiencies for local charged track triggers, for hit and for segments reconstruction were measured, and are above 99%. The timing resolution per layer is approximately 5 ns

    Performance of CMS muon reconstruction in pp collision events at sqrt(s) = 7 TeV

    Get PDF
    The performance of muon reconstruction, identification, and triggering in CMS has been studied using 40 inverse picobarns of data collected in pp collisions at sqrt(s) = 7 TeV at the LHC in 2010. A few benchmark sets of selection criteria covering a wide range of physics analysis needs have been examined. For all considered selections, the efficiency to reconstruct and identify a muon with a transverse momentum pT larger than a few GeV is above 95% over the whole region of pseudorapidity covered by the CMS muon system, abs(eta) < 2.4, while the probability to misidentify a hadron as a muon is well below 1%. The efficiency to trigger on single muons with pT above a few GeV is higher than 90% over the full eta range, and typically substantially better. The overall momentum scale is measured to a precision of 0.2% with muons from Z decays. The transverse momentum resolution varies from 1% to 6% depending on pseudorapidity for muons with pT below 100 GeV and, using cosmic rays, it is shown to be better than 10% in the central region up to pT = 1 TeV. Observed distributions of all quantities are well reproduced by the Monte Carlo simulation.Comment: Replaced with published version. Added journal reference and DO

    Measurement of the t(t)over-bar production cross section in the dilepton channel in pp collisions at √s=8 TeV

    Get PDF
    The top-antitop quark (t (t) over bar) production cross section is measured in proton-proton collisions at root s = 8 TeV with the CMS experiment at the LHC, using a data sample corresponding to an integrated luminosity of 5.3 fb(-1). The measurement is performed by analysing events with a pair of electrons or muons, or one electron and one muon, and at least two jets, one of which is identified as originating from hadronisation of a bottom quark. The measured cross section is 239 +/- 2 (stat.) +/- 11 (syst.) +/- 6 (lum.) pb, for an assumed top-quark mass of 172.5 GeV, in agreement with the prediction of the standard model

    Performance of CMS muon reconstruction in pp collision events at sqrt(s) = 7 TeV

    Get PDF
    The performance of muon reconstruction, identification, and triggering in CMS has been studied using 40 inverse picobarns of data collected in pp collisions at sqrt(s) = 7 TeV at the LHC in 2010. A few benchmark sets of selection criteria covering a wide range of physics analysis needs have been examined. For all considered selections, the efficiency to reconstruct and identify a muon with a transverse momentum pT larger than a few GeV is above 95% over the whole region of pseudorapidity covered by the CMS muon system, abs(eta) < 2.4, while the probability to misidentify a hadron as a muon is well below 1%. The efficiency to trigger on single muons with pT above a few GeV is higher than 90% over the full eta range, and typically substantially better. The overall momentum scale is measured to a precision of 0.2% with muons from Z decays. The transverse momentum resolution varies from 1% to 6% depending on pseudorapidity for muons with pT below 100 GeV and, using cosmic rays, it is shown to be better than 10% in the central region up to pT = 1 TeV. Observed distributions of all quantities are well reproduced by the Monte Carlo simulation.Comment: Replaced with published version. Added journal reference and DO

    Cardiorespiratory evaluation in pre and post operative moments of laparoscopic cholecystectomy

    Get PDF
    PURPOSE: To analyze the changes in both respiratory function and cardiopulmonary exercise tests results in patients subjected to laparoscopic cholecystectomy. METHODS: Fifty patients were evaluated (76% women) and the average age was 47.8±14.2 years. All individuals underwent the measurement of spirometry, manovacuometry, 6-minute walk test (6MWT) and stair-climbing test (SCT). All tests were performed at the first (PO1), fifth (PO5) and thirtieth (PO30) postoperative days. RESULTS: BMI average was 28.8±4.8 kg/m2. Sample comprised 68% non-smokers, 20% current smokers, and 12% former smokers. There was no incidence of postoperative complication whatsoever. There was a significant decrease in spirometric values at PO1, but values were similar to the ones of PRE at PO30. Manovacuometry showed alterations at PO1 displaying values that were similar to the ones of PRE at PO30. 6MWT was significantly shorter at until PO5, but at PO30 values were similar to ones of PRE. As for SCT, values were significantly compromised at PO5 and PO30 since they were similar to the ones of PRE. CONCLUSION: Patients submitted to laparoscopic cholecystectomy present a decrease in cardiorespiratory function on the first postoperative moments but there is a rapid return to preoperative conditions.Sao Paulo State University Botucatu School of MedicineUNESP Botucatu School of MedicineSao Paulo State University Botucatu School of MedicineUNESP Botucatu School of Medicin

    Identification and Filtering of Uncharacteristic Noise in the CMS Hadron Calorimeter

    Get PDF
    VertaisarvioitupeerReviewe

    Chronic adaptations of lung function in breath-hold diving fishermen

    Full text link
    Objectives: The aim of this study was to verify and analyze the existence of chronic adaptations of lung function in freediving fishermen whose occupation is artisanal fishing. Material and Methods: This was a cross-sectional study involving 11 breath-hold diving fishermen and 10 non-breath-hold diving fishermen (control) from the village of Bitupitá in the municipality of Barroquinha (Ceará - Brazil). Anthropometric measurements, chest and abdominal circumferences as well as spirometric and respiratory muscle strength tests were conducted according to the specifications of the American Thoracic Society/European Respiratory Society (ATS/ERS). In order to compare the measured values versus the predicted values, Student t test was used in the case of parametric test and Wilcoxon test in the case of nonparametric test. To compare the inter-group means Student t test was used for parametric test and Mann-Whitney test for the nonparametric one. The level of significance was set at α = 5%. Results: The forced vital capacity (FVC) (4.9±0.6 l vs. 4.3±0.4 l) and forced expiratory volume in 1 s (FEV1) (4.0±0.5 l vs. 3.6±0.3 l) were, respectively, higher in the group of divers compared to the control group (p ≤ 0.05). Furthermore, in the group of free divers, the measured FVC, FEV1 and FEV1/FVC ratios were significantly greater than the predicted ones. No differences were found between the measured respiratory pressures. Conclusions: These results indicate that breath-hold diving seems to produce chronic adaptations of the respiratory system, resulting in elevated lung volumes with no airway obstruction

    Effects of non-invasive ventilatory support in tolerance to the effort of patients with hemodialysis

    Full text link
    Abstract Introduction The kidney system is responsible for the maintenance of homeostasis and in patients with Chronic Kidney Disease the kidney functions changes, contributing for the development of various complications that will have adverse effects in tolerance to the physical exercise and in Quality of Life of this patients. Objective To evaluate the Effects of non-invasive ventilatory support in tolerance to the patients&#8217; physical exercise in dialysis. Methods The patients performed two 6-minute walk tests, following an adapted protocol for treadmill, one of them without the use of non-invasive ventilatory support and the other with non-invasive ventilatory support during the walk. Besides, the patients answered a questionnaire of quality of life and the KDQOL-SFTM specific for the population under study. Results It was noticed that there was not statistical difference in the distance recorded during the 6-minute walk tests. Regarding the quality of life, the greater impact of the disease was in relation to &#8220;Professional Activity&#8221;. Conclusion In conclusion, a non-invasive ventilatory support did not cause significant effects in tolerance to the exercise of this population. However, we should take into consideration the limitations suffered during the research development
    corecore