8 research outputs found

    Hadronic vacuum polarization contribution to the anomalous magnetic moments of leptons from first principles

    Get PDF
    We compute the leading, strong-interaction contribution to the anomalous magnetic moment of the electron, muon and tau using lattice quantum chromodynamics (QCD) simulations. Calculations include the effects of uu, dd, ss and cc quarks and are performed directly at the physical values of the quark masses and in volumes of linear extent larger than 6 fm6\,\mathrm{fm}. All connected and disconnected Wick contractions are calculated. Continuum limits are carried out using six lattice spacings. We obtain aeLO−HVP=189.3(2.6)(5.6)×10−14a_e^\mathrm{LO-HVP}=189.3(2.6)(5.6)\times 10^{-14}, aÎŒLO−HVP=711.1(7.5)(17.4)×10−10a_\mu^\mathrm{LO-HVP}=711.1(7.5)(17.4)\times 10^{-10} and aτLO−HVP=341.0(0.8)(3.2)×10−8a_\tau^\mathrm{LO-HVP}=341.0(0.8)(3.2)\times 10^{-8}, where the first error is statistical and the second is systematic.Comment: 17 pages, 8 figures (in 13 PDF files), RevTeX 4.1. Minor changes to results and to text. References updated. Matches version published in Physical Review Letter

    Slope and curvature of the hadronic vacuum polarization at vanishing virtuality from lattice QCD

    Get PDF
    6 pages, 3 figuresInternational audienceWe compute the slope and curvature, at vanishing four-momentum transfer squared, of the leading order hadron vacuum polarization function, using lattice QCD. Calculations are performed with 2+1+1 flavors of staggered fermions directly at the physical values of the quark masses and in volumes of linear extent larger than 6fm. The continuum limit is carried out using six different lattice spacings. All connected and disconnected contributions are calculated, up to and including those of the charm

    Disconnected hadronic contribution to the muon magnetic moment at the physical point

    No full text
    We compute the slope and curvature, at vanishing four-momentum transfer squared, of the disconnected contribution of the leading order hadron vacuum polarization function, using lattice QCD. Calculations are performed with 2 + 1 + 1 flavors of staggered fermions directly at the physical values of the quark masses and in volumes of linear extent larger than 6 fm. The continuum limit is carried out using five different lattice spacings

    Body mass index and complications following major gastrointestinal surgery: a prospective, international cohort study and meta-analysis.

    No full text
    AIM: Previous studies reported conflicting evidence on the effects of obesity on outcomes after gastrointestinal surgery. The aims of this study were to explore the relationship of obesity with major postoperative complications in an international cohort and to present a meta-analysis of all available prospective data. METHODS: This prospective, multicentre study included adults undergoing both elective and emergency gastrointestinal resection, reversal of stoma or formation of stoma. The primary end-point was 30-day major complications (Clavien-Dindo Grades III-V). A systematic search was undertaken for studies assessing the relationship between obesity and major complications after gastrointestinal surgery. Individual patient meta-analysis was used to analyse pooled results. RESULTS: This study included 2519 patients across 127 centres, of whom 560 (22.2%) were obese. Unadjusted major complication rates were lower in obese vs normal weight patients (13.0% vs 16.2%, respectively), but this did not reach statistical significance (P = 0.863) on multivariate analysis for patients having surgery for either malignant or benign conditions. Individual patient meta-analysis demonstrated that obese patients undergoing surgery for malignancy were at increased risk of major complications (OR 2.10, 95% CI 1.49-2.96, P < 0.001), whereas obese patients undergoing surgery for benign indications were at decreased risk (OR 0.59, 95% CI 0.46-0.75, P < 0.001) compared to normal weight patients. CONCLUSIONS: In our international data, obesity was not found to be associated with major complications following gastrointestinal surgery. Meta-analysis of available prospective data made a novel finding of obesity being associated with different outcomes depending on whether patients were undergoing surgery for benign or malignant disease

    Body mass index and complications following major gastrointestinal surgery: A prospective, international cohort study and meta-analysis

    Get PDF
    Aim Previous studies reported conflicting evidence on the effects of obesity on outcomes after gastrointestinal surgery. The aims of this study were to explore the relationship of obesity with major postoperative complications in an international cohort and to present a metaanalysis of all available prospective data. Methods This prospective, multicentre study included adults undergoing both elective and emergency gastrointestinal resection, reversal of stoma or formation of stoma. The primary end-point was 30-day major complications (Clavien\u2013Dindo Grades III\u2013V). A systematic search was undertaken for studies assessing the relationship between obesity and major complications after gastrointestinal surgery. Individual patient meta-analysis was used to analyse pooled results. Results This study included 2519 patients across 127 centres, of whom 560 (22.2%) were obese. Unadjusted major complication rates were lower in obese vs normal weight patients (13.0% vs 16.2%, respectively), but this did not reach statistical significance (P = 0.863) on multivariate analysis for patients having surgery for either malignant or benign conditions. Individual patient meta-analysis demonstrated that obese patients undergoing surgery formalignancy were at increased risk of major complications (OR 2.10, 95% CI 1.49\u20132.96, P &lt; 0.001), whereas obese patients undergoing surgery for benign indications were at decreased risk (OR 0.59, 95% CI 0.46\u20130.75, P &lt; 0.001) compared to normal weight patients. Conclusions In our international data, obesity was not found to be associated with major complications following gastrointestinal surgery. Meta-analysis of available prospective data made a novel finding of obesity being associated with different outcomes depending on whether patients were undergoing surgery for benign or malignant disease

    Bibliographische Notizen und Mitteilungen

    No full text
    corecore