| 1. |
- 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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| 3. |
- Haftenberger, M, et al.
(författare)
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Physical activity of subjects aged 50-64 years involved in the European Prospective Investigation into Cancer and Nutrition (EPIC)
- 2002
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Ingår i: Public Health Nutrition. - 1475-2727. ; 5:6B, s. 1163-1177
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Tidskriftsartikel (refereegranskat)abstract
- Objective: To describe physical activity of participants in the European Prospective Investigation into Cancer and Nutrition (EPIC). Design: A cross-sectional analysis of baseline data of a European prospective cohort study. Subjects: This analysis was restricted to participants in the age group 50-64 years, which was represented in all EPIC centres. It involved 236 386 participants from 25 centres in nine countries. In each EPIC centre, physical activity was assessed by standardised and validated questions. Frequency distribution of type of professional activity and participation in non-professional activities, and age-adjusted means, medians and percentiles of time dedicated to non-professional activities are presented for men and women from each centre. Results: Professional activity was most frequently classified as sedentary or standing in all centres. There was a wide variation regarding participation in different types of non-professional activities and time dedicated to these activities across EPIC centres. Over 80% of all EPIC participants engaged in walking, while less than 50% of the subjects participated in sport. Total time dedicated to recreational activities was highest among the Dutch participants and lowest among men from Malmo (Sweden) and women from Naples (Italy). In all centres, total time dedicated to recreational activity in the summer was higher than in the winter. Women from southern Europe spent the most time on housekeeping. Conclusions: There is a considerable variation of physical activity across EPIC centres. This variation was especially evident for recreational activities in both men and women.
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