474 research outputs found

    Issues Concerning Loop Corrections to the Primordial Power Spectra

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    We expound ten principles in an attempt to clarify the debate over infrared loop corrections to the primordial scalar and tensor power spectra from inflation. Among other things we note that existing proposals for nonlinear extensions of the scalar fluctuation field ζ\zeta introduce new ultraviolet divergences which no one understands how to renormalize. Loop corrections and higher correlators of these putative observables would also be enhanced by inverse powers of the slow roll parameter ϵ\epsilon. We propose an extension which should be better behaved.Comment: 36 pages, uses LaTeX2e, version 3 revised for publication with a much expanded section 4, proving that our proposed extension of the zeta-zeta correlator absorbs the one loop infrared divergences from graviton

    The Hubble Effective Potential

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    We generalize the effective potential to scalar field configurations which are proportional to the Hubble parameter of a homogeneous and isotropic background geometry. This may be useful in situations for which curvature effects are significant. We evaluate the one loop contribution to the Hubble Effective Potential for a massless scalar with arbitrary conformal and quartic couplings, on a background for which the deceleration parameter is constant. Among other things, we find that inflationary particle production leads to symmetry restoration at late times.Comment: 32 pages, 6 figures, version 2 published in JCAP with some typoes corrected and two additional reference

    Cardio-Renal-Metabolic Overlap, Outcomes, and Dapagliflozin in Heart Failure With Mildly Reduced or Preserved Ejection Fraction

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    Background: Cardio-renal-metabolic (CRM) conditions are individually common among patients with heart failure (HF), but the prevalence and influence of overlapping CRM conditions in this population have not been well-studied. Objectives: This study aims to evaluate the impact of overlapping CRM conditions on clinical outcomes and treatment effects of dapagliflozin in HF. Methods: In this post hoc analysis of DELIVER (Dapagliflozin Evaluation to Improve the Lives of Patients With Preserved Ejection Fraction Heart Failure), we evaluated the prevalence of comorbid CRM conditions (atherosclerotic cardiovascular disease, chronic kidney disease, and type 2 diabetes), their impact on the primary outcome (cardiovascular death or worsening HF), and treatment effects of dapagliflozin by CRM status. Results: Among 6,263 participants, 1,952 (31%), 2,245 (36%), and 1,236 (20%) had 1, 2, and 3 additional CRM conditions, respectively. HF alone was uncommon (13%). Greater CRM multimorbidity was associated with older age, higher body mass index, longer-duration HF, worse health status, and lower left ventricular ejection fraction. Risk of the primary outcome increased with higher CRM overlap, with 3 CRM conditions independently associated with highest risk of primary events (adjusted HR: 2.16 [95% CI: 1.72-2.72]; P &lt; 0.001) compared with HF alone. Relative benefits of dapagliflozin on the primary outcome were consistent irrespective of the type of CRM overlap (Pinteraction = 0.773) and by the number of CRM conditions (Pinteraction = 0.734), with greatest absolute benefits among those with highest CRM multimorbidity. Estimated 2-year numbers needed to treat with dapagliflozin to prevent 1 primary event were approximately 52, 39, 33, and 24 for participants with 0, 1, 2, and 3 additional CRM conditions at baseline, respectively. Adverse events between treatment arms were similar across the CRM spectrum. Conclusions: CRM multimorbidity was common and associated with adverse outcomes among patients with HF and left ventricular ejection fraction &gt;40% in DELIVER. Dapagliflozin was safe and effective across the CRM spectrum, with greater absolute benefits among those with highest CRM overlap (Dapagliflozin Evaluation to Improve the LIVEs of Patients With Preserved Ejection Fraction Heart Failure [DELIVER]; NCT03619213).</p

    Effects of Dapagliflozin in Patients in Asia:A Post Hoc Subgroup Analysis From the DELIVER Trial

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    Background: Patients with heart failure (HF) with mildly reduced or preserved ejection fraction in Asia may have different clinical characteristics and outcomes compared with patients from other parts of the world.Objectives: The purpose of this study was to investigate the clinical characteristics, safety, and efficacy of dapagliflozin in patients in Asia vs outside Asia in the DELIVER (Dapagliflozin Evaluation to Improve the Lives of Patients with Preserved Ejection Fraction Heart Failure) trial. Methods: In the DELIVER trial, patients with HF and left ventricular ejection fraction &gt;40% were enrolled across 353 sites in 20 countries. The effects of dapagliflozin vs placebo on primary (composite of worsening HF or cardiovascular death) and secondary outcomes were compared in patients from Asia vs outside Asia. Results: Among 6,263 participants, 1,226 (19.6%) were enrolled in Asia. Participants from Asia were less likely to have diabetes, hypertension, history of myocardial infarction, or obesity. After adjusting for clinically relevant characteristics, those in Asia had similar risks of primary composite outcome compared with those from outside Asia (HR: 0.97; 95% CI: 0.82-1.15). Those in Asia had a lower risk of all-cause mortality compared with those enrolled outside Asia (HR: 0.54; 95% CI: 0.44-0.66). Enrollment from Asia did not modify the effect of dapagliflozin on the primary outcome (Pinteraction = 0.54). Serious adverse events and rates of drug discontinuation were also balanced in both treatment arms, irrespective of enrollment in Asia vs outside Asia. Conclusions: In the global DELIVER trial, dapagliflozin reduced the risk of CV death or worsening HF events and was well tolerated among participants enrolled in both Asia and other geographic regions.</p

    Evidence of Color Coherence Effects in W+jets Events from ppbar Collisions at sqrt(s) = 1.8 TeV

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    We report the results of a study of color coherence effects in ppbar collisions based on data collected by the D0 detector during the 1994-1995 run of the Fermilab Tevatron Collider, at a center of mass energy sqrt(s) = 1.8 TeV. Initial-to-final state color interference effects are studied by examining particle distribution patterns in events with a W boson and at least one jet. The data are compared to Monte Carlo simulations with different color coherence implementations and to an analytic modified-leading-logarithm perturbative calculation based on the local parton-hadron duality hypothesis.Comment: 13 pages, 6 figures. Submitted to Physics Letters

    Search for direct production of charginos and neutralinos in events with three leptons and missing transverse momentum in √s = 7 TeV pp collisions with the ATLAS detector

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    A search for the direct production of charginos and neutralinos in final states with three electrons or muons and missing transverse momentum is presented. The analysis is based on 4.7 fb−1 of proton–proton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with Standard Model expectations in three signal regions that are either depleted or enriched in Z-boson decays. Upper limits at 95% confidence level are set in R-parity conserving phenomenological minimal supersymmetric models and in simplified models, significantly extending previous results

    Measurement of the polarisation of W bosons produced with large transverse momentum in pp collisions at sqrt(s) = 7 TeV with the ATLAS experiment

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    This paper describes an analysis of the angular distribution of W->enu and W->munu decays, using data from pp collisions at sqrt(s) = 7 TeV recorded with the ATLAS detector at the LHC in 2010, corresponding to an integrated luminosity of about 35 pb^-1. Using the decay lepton transverse momentum and the missing transverse energy, the W decay angular distribution projected onto the transverse plane is obtained and analysed in terms of helicity fractions f0, fL and fR over two ranges of W transverse momentum (ptw): 35 < ptw < 50 GeV and ptw > 50 GeV. Good agreement is found with theoretical predictions. For ptw > 50 GeV, the values of f0 and fL-fR, averaged over charge and lepton flavour, are measured to be : f0 = 0.127 +/- 0.030 +/- 0.108 and fL-fR = 0.252 +/- 0.017 +/- 0.030, where the first uncertainties are statistical, and the second include all systematic effects.Comment: 19 pages plus author list (34 pages total), 9 figures, 11 tables, revised author list, matches European Journal of Physics C versio

    Observation of a new chi_b state in radiative transitions to Upsilon(1S) and Upsilon(2S) at ATLAS

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    The chi_b(nP) quarkonium states are produced in proton-proton collisions at the Large Hadron Collider (LHC) at sqrt(s) = 7 TeV and recorded by the ATLAS detector. Using a data sample corresponding to an integrated luminosity of 4.4 fb^-1, these states are reconstructed through their radiative decays to Upsilon(1S,2S) with Upsilon->mu+mu-. In addition to the mass peaks corresponding to the decay modes chi_b(1P,2P)->Upsilon(1S)gamma, a new structure centered at a mass of 10.530+/-0.005 (stat.)+/-0.009 (syst.) GeV is also observed, in both the Upsilon(1S)gamma and Upsilon(2S)gamma decay modes. This is interpreted as the chi_b(3P) system.Comment: 5 pages plus author list (18 pages total), 2 figures, 1 table, corrected author list, matches final version in Physical Review Letter

    Search for displaced vertices arising from decays of new heavy particles in 7 TeV pp collisions at ATLAS

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    We present the results of a search for new, heavy particles that decay at a significant distance from their production point into a final state containing charged hadrons in association with a high-momentum muon. The search is conducted in a pp-collision data sample with a center-of-mass energy of 7 TeV and an integrated luminosity of 33 pb^-1 collected in 2010 by the ATLAS detector operating at the Large Hadron Collider. Production of such particles is expected in various scenarios of physics beyond the standard model. We observe no signal and place limits on the production cross-section of supersymmetric particles in an R-parity-violating scenario as a function of the neutralino lifetime. Limits are presented for different squark and neutralino masses, enabling extension of the limits to a variety of other models.Comment: 8 pages plus author list (20 pages total), 8 figures, 1 table, final version to appear in Physics Letters

    Measurement of the inclusive isolated prompt photon cross-section in pp collisions at sqrt(s)= 7 TeV using 35 pb-1 of ATLAS data

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    A measurement of the differential cross-section for the inclusive production of isolated prompt photons in pp collisions at a center-of-mass energy sqrt(s) = 7 TeV is presented. The measurement covers the pseudorapidity ranges |eta|<1.37 and 1.52<=|eta|<2.37 in the transverse energy range 45<=E_T<400GeV. The results are based on an integrated luminosity of 35 pb-1, collected with the ATLAS detector at the LHC. The yields of the signal photons are measured using a data-driven technique, based on the observed distribution of the hadronic energy in a narrow cone around the photon candidate and the photon selection criteria. The results are compared with next-to-leading order perturbative QCD calculations and found to be in good agreement over four orders of magnitude in cross-section.Comment: 7 pages plus author list (18 pages total), 2 figures, 4 tables, final version published in Physics Letters
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