1,785 research outputs found

    Search for electroweak SUSY production at CMS

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    Using the data collected during Run I of LHC operation the CMS Collaboration performed multiple analyses searching for the direct electroweak production of supersymmetric particles in proton-proton collisions. Different decay modes of the gauginos and sleptons were considered, through intermediate vector bosons or Higgs bosons, or directly to leptons. A set of complementary searches were designed to target these different decays. None of these searches shows any indication for physics beyond the standard model.Comment: On behalf of the CMS Collaboration Presented at The Second Annual Conference on Large Hadron Collider Physics, Columbia University, New York, U.S.A, June 2-7, 201

    Comparison of functional outcome after extended versus super-extended pelvic lymph node dissection during radical prostatectomy in high-risk localized prostate cancer

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    Background: Urinary continence and erectile function (EF) are best preserved whenmeticulous dissection of prostate and nerve sparing technique are used during radicalprostatectomy (RP). However, extent of lymph node dissection (LND) may also adverselyaffect functional results.Objective: To determine whether performing a super-extended LND (seLND) has asignificant effect on recovery of urinary continence and EF after RP.Design, setting, and participants: All patients who underwent RP from January 2007until December 2013 were handed questionnaires assessing continence and EF. Allpatients in whom at least an extended LND (eLND) was performed were selected. Thissearch yielded 526 patients. 172 of these patients had filed out 2 or more questionnairesand were included in our analysis.Outcome measurements and statistical analysis: All questionnaires were reviewed.We used Kaplan–Meier analyses and multivariate Cox analysis to assess the differencein recovery of continence and EF over time for eLND/seLND. Primary endpoints were fullrecovery of continence (no loss of urine) and full recovery of EF (successful intercoursepossible). Patients who did not reach the endpoint when the last questionnaire was filledout were censored at that time. Median follow-up was 12.43 months for continence, and18.97 months for EF.results and limitations: Patients undergoing seLND have a lower chance of regainingboth urinary continence [hazard ratio (HR) 0.59, 95% CI 0.39–0.90, p = 0.026] and EF(HR 0.28, 95% CI 0.13–0.57, p = 0.009). Age at surgery had a significant influence onboth continence and EF in multivariate analysis. Major limitation of the study was that noformal preoperative assessment of continence and potency was done.conclusion: Extending the LND template beyond the eLND template may cause atleast a significant delay in recovery of urinary continence and leads to less recovery of EF.</p

    Measurement of the charge ratio of atmospheric muons with the CMS detector

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    We present a measurement of the ratio of positive to negative muon fluxes from cosmic ray interactions in the atmosphere, using data collected by the CMS detector both at ground level and in the underground experimental cavern at the CERN LHC. Muons were detected in the momentum range from 5 GeV/c to 1 TeV/c . The surface flux ratio is measured to be 1.2766±0.0032(stat.)±0.0032(syst.), independent of the muon momentum, below 100 GeV/c. This is the most precise measurement to date. At higher momenta the data are consistent with an increase of the charge ratio, in agreement with cosmic ray shower models and compatible with previous measurements by deep-underground experiments.United States. Dept. of EnergyNational Science Foundation (U.S.)Alfred P. Sloan Foundatio

    Observation of long-range, near-side angular correlations in proton-proton collisions at the LHC

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    Results on two-particle angular correlations for charged particles emitted in proton-proton collisions at center-of-mass energies of 0.9, 2.36, and 7 TeV are presented, using data collected with the CMS detector over a broad range of pseudorapidity (η) and azimuthal angle (ϕ). Short-range correlations in Δη, which are studied in minimum bias events, are characterized using a simple “independent cluster” parametrization in order to quantify their strength (cluster size) and their extent in η (cluster decay width). Long-range azimuthal correlations are studied differentially as a function of charged particle multiplicity and particle transverse momentum using a 980 nb[superscript −1] data set at 7 TeV. In high multiplicity events, a pronounced structure emerges in the two-dimensional correlation function for particle pairs with intermediate p [subscript T] of 1–3 GeV/c, 2.0 < |Δη| < 4.8 and Δϕ ≈ 0. This is the first observation of such a long-range, near-side feature in two-particle correlation functions in pp or p[−over]p collisions

    Search for supersymmetry in pp collisions at 7 TeV in events with jets and missing transverse energy

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    A search for supersymmetry with R-parity conservation in proton–proton collisions at a centre-of-mass energy of 7 TeV is presented. The data correspond to an integrated luminosity of 35 pb[superscript -1] collected by the CMS experiment at the LHC. The search is performed in events with jets and significant missing transverse energy, characteristic of the decays of heavy, pair-produced squarks and gluinos. The primary background, from standard model multijet production, is reduced by several orders of magnitude to a negligible level by the application of a set of robust kinematic requirements. With this selection, the data are consistent with the standard model backgrounds, namely t [bar over t], W + jet and Z + jet production, which are estimated from data control samples. Limits are set on the parameters of the constrained minimal supersymmetric extension of the standard model. These limits extend those set previously by experiments at the Tevatron and LEP colliders.European Organization for Nuclear ResearchUnited States. Dept. of EnergyNational Science Foundation (U.S.

    Search for microscopic black hole signatures at the Large Hadron Collider

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    A search for microscopic black hole production and decay in pp collisions at a center-of-mass energy of 7 TeV has been conducted by the CMS Collaboration at the LHC, using a data sample corresponding to an integrated luminosity of 35 pb[superscript −1]. Events with large total transverse energy are analyzed for the presence of multiple high-energy jets, leptons, and photons, typical of a signal expected from a microscopic black hole. Good agreement with the standard model backgrounds, dominated by QCD multijet production, is observed for various final-state multiplicities and model-independent limits on new physics in these final states are set. Using simple semi-classical approximation, limits on the minimum black hole mass are derived as well, in the range 3.5–4.5 TeV. These are the first direct limits on black hole production at a particle accelerator.European Organization for Nuclear ResearchNational Science Foundation (U.S.)United States. Dept. of Energ

    Discrimination, Reliability, Sensitivity, and Specificity of Robotic Surgical Proficiency Assessment With Global Evaluative Assessment of Robotic Skills and Binary Scoring Metrics: Results From a Randomized Controlled Trial

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    Objective: To compare binary metrics and Global Evaluative Assessment of Robotic Skills (GEARS) evaluations of training outcome assessments for reliability, sensitivity, and specificity. Background: GEARS–Likert-scale skills assessment are a widely accepted tool for robotic surgical training outcome evaluations. Proficiency-based progression (PBP) training is another methodology but uses binary performance metrics for evaluations. Methods: In a prospective, randomized, and blinded study, we compared conventional with PBP training for a robotic suturing, knot-tying anastomosis task. Thirty-six surgical residents from 16 Belgium residency programs were randomized. In the skills laboratory, the PBP group trained until they demonstrated a quantitatively defined proficiency benchmark. The conventional group were yoked to the same training time but without the proficiency requirement. The final trial was video recorded and assessed with binary metrics and GEARS by robotic surgeons blinded to individual, group, and residency program. Sensitivity and specificity of the two assessment methods were evaluated with area under the curve (AUC) and receiver operating characteristics (ROC) curves. Results: The PBP group made 42% fewer objectively assessed performance errors than the conventional group (P &lt; 0.001) and scored 15% better on the GEARS assessment (P = 0.033). The mean interrater reliability for binary metrics and GEARS was 0.87 and 0.38, respectively. Binary total error metrics AUC was 97% and for GEARS 85%. With a sensitivity threshold of 0.8, false positives rates were 3% and 25% for, respectively, the binary and GEARS assessments. Conclusions: Binary metrics for scoring a robotic VUA task demonstrated better psychometric properties than the GEARS assessment. </jats:sec

    Measurement of the differential dijet production cross section in proton–proton collisions at √s = 7 TeV

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    A measurement of the double-differential inclusive dijet production cross section in proton–proton collisions at √s = 7 TeV is presented as a function of the dijet invariant mass and jet rapidity. The data correspond to an integrated luminosity of 36 pb[superscript −1], recorded with the CMS detector at the LHC. The measurement covers the dijet mass range 0.2 TeV to 3.5 TeV and jet rapidities up to |y|=2.5. It is found to be in good agreement with next-to-leading-order QCD predictions.United States. Dept. of EnergyNational Science Foundation (U.S.

    Pseudorapidity and transverse momentum dependence of flow harmonics in pPb and PbPb collisions

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