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- Schael, S, et al.
(författare)
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Precision electroweak measurements on the Z resonance
- 2006
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Ingår i: Physics Reports. - : Elsevier BV. - 0370-1573 .- 1873-6270. ; 427:5-6, s. 257-454
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Forskningsöversikt (refereegranskat)abstract
- We report on the final electroweak measurements performed with data taken at the Z resonance by the experiments operating at the electron-positron colliders SLC and LEP. The data consist of 17 million Z decays accumulated by the ALEPH, DELPHI, L3 and OPAL experiments at LEP, and 600 thousand Z decays by the SLID experiment using a polarised beam at SLC. The measurements include cross-sections, forward-backward asymmetries and polarised asymmetries. The mass and width of the Z boson, m(Z) and Gamma(Z), and its couplings to fermions, for example the p parameter and the effective electroweak mixing angle for leptons, are precisely measured: m(Z) = 91.1875 +/- 0.0021 GeV, Gamma(Z) = 2.4952 +/- 0.0023 GeV, rho(l) = 1.0050 +/- 0.0010, sin(2)theta(eff)(lept) = 0.23153 +/- 0.00016. The number of light neutrino species is determined to be 2.9840 +/- 0.0082, in agreement with the three observed generations of fundamental fermions. The results are compared to the predictions of the Standard Model (SM). At the Z-pole, electroweak radiative corrections beyond the running of the QED and QCD coupling constants are observed with a significance of five standard deviations, and in agreement with the Standard Model. Of the many Z-pole measurements, the forward-backward asymmetry in b-quark production shows the largest difference with respect to its SM expectation, at the level of 2.8 standard deviations. Through radiative corrections evaluated in the framework of the Standard Model, the Z-pole data are also used to predict the mass of the top quark, m(t) = 173(+10)(+13) GeV, and the mass of the W boson, m(W) = 80.363 +/- 0.032 GeV. These indirect constraints are compared to the direct measurements, providing a stringent test of the SM. Using in addition the direct measurements of m(t) and m(W), the mass of the as yet unobserved SM Higgs boson is predicted with a relative uncertainty of about 50% and found to be less than 285 GeV at 95% confidence level. (c) 2006 Elsevier B.V. All rights reserved.
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| 2. |
- Breeman, Arno, et al.
(författare)
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Treatment decisions in stable coronary artery disease : insights from the Euro Heart Survey on Coronary Revascularization
- 2006
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Ingår i: Journal of Thoracic and Cardiovascular Surgery. - : Elsevier BV. - 0022-5223 .- 1097-685X. ; 132:5, s. 1001-1009
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Tidskriftsartikel (refereegranskat)abstract
- Objective: We sought to assess determinants of clinical decision making in patients with stable coronary artery disease. Methods: The 2936 patients with stable angina pectoris who enrolled in the Euro Heart Survey on Coronary Revascularization were the subject of this analysis. After the diagnosis has been confirmed, physicians decided on treatment: medical management or revascularization therapy by means of percutaneous coronary intervention or coronary bypass surgery. We applied logistic regression analyses to evaluate the relation between baseline characteristics and treatment decision: medical treatment versus percutaneous coronary intervention, medical treatment versus coronary bypass surgery, and percutaneous coronary intervention versus coronary bypass surgery. Results: The median age was 64 years, 77% were men, and 20% had diabetes. Medical therapy was intended in 690 (24%) patients, percutaneous coronary intervention in 1503 (51%) patients, and coronary bypass surgery in the remaining 743 (25%) patients, respectively. Revascularization was generally preferred in patients with more severe anginal complaints, an intermediate-to-large area of myocardium at risk, and preserved left ventricular function who had not undergone prior coronary revascularization, provided lesions were suitable for treatment. Coronary bypass surgery was preferred over percutaneous coronary intervention in multivessel or left main disease, as well as in those with concomitant valvular heart disease, provided a sufficient number of lesions were suitable for coronary bypass surgery. In those with previous coronary bypass surgeries, more often percutaneous coronary intervention was preferred than redo coronary bypass surgery. Diabetes was not associated with more frequent preference for coronary bypass surgery. Conclusions: In the hospitals that participated in the Euro Heart Survey on Coronary Revascularization, treatment decisions in stable coronary artery disease were largely in agreement with professional guidelines and determined by multiple factors. Most important deviations between guideline recommendations and clinical practice were seen in patients with extensive coronary disease, impaired left ventricular function, and diabetes.
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