| 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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| 2. |
- Abbasi, R., et al.
(författare)
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The IceCube data acquisition system : Signal capture, digitization, and timestamping
- 2009
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Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier BV. - 0168-9002 .- 1872-9576. ; 601:3, s. 294-316
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Tidskriftsartikel (refereegranskat)abstract
- IceCube is a km-scale neutrino observatory under construction at the South Pole with sensors both in the deep ice (InIce) and on the surface (IceTop). The sensors, called Digital Optical Modules (DOMs). detect, digitize and timestamp the signals from optical Cherenkov-radiation photons. The DOM Main Board (MB) data acquisition subsystem is connected to the central DAQ in the IceCube Laboratory (ICL) by a single twisted copper wire-pair and transmits packetized data on demand. Time calibration is maintained throughout the array by regular transmission to the DOMs of precisely timed analog signals, synchronized to a central GPS-disciplined clock. The design goals and consequent features, functional capabilities, and initial performance of the DOM MB, and the operation of a combined array of DOMs as a system, are described here. Experience with the first InIce strings and the IceTop stations indicates that the system design and performance goals have been achieved. (c) 2009 Elsevier B.V. All rights reserved.
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| 3. |
- Abbasi, R., et al.
(författare)
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Search for point sources of high energy neutrinos with final data from AMANDA-II
- 2009
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Ingår i: Physical Review D. - 1550-7998 .- 1550-2368. ; 79, s. 062001-
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Tidskriftsartikel (refereegranskat)abstract
- We present a search for point sources of high energy neutrinos using 3.8 yr of data recorded by AMANDA-II during 2000-2006. After reconstructing muon tracks and applying selection criteria designed to optimally retain neutrino-induced events originating in the northern sky, we arrive at a sample of 6595 candidate events, predominantly from atmospheric neutrinos with primary energy 100 GeV to 8 TeV. Our search of this sample reveals no indications of a neutrino point source. We place the most stringent limits to date on E(-2) neutrino fluxes from points in the northern sky, with an average upper limit of E(2)Phi(nu mu)+nu(tau)<= 5.2x10(-11) TeV cm(-2) s(-1) on the sum of nu(mu) and nu(tau) fluxes, assumed equal, over the energy range from 1.9 TeV to 2.5 PeV.
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| 4. |
- Alexander, John H., et al.
(författare)
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Apixaban, an oral, direct, selective factor Xa inhibitor, in combination with antiplatelet therapy after acute coronary syndrome : results of the Apixaban for Prevention of Acute Ischemic and Safety Events (APPRAISE) trial
- 2009
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Ingår i: Circulation. - 0009-7322 .- 1524-4539. ; 119:22, s. 2877-2885
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: After an acute coronary syndrome, patients remain at risk of recurrent events. Apixaban, an oral direct factor Xa inhibitor, is a novel anticoagulant that may reduce these events but also poses a risk of bleeding. METHODS AND RESULTS: Apixaban for Prevention of Acute Ischemic and Safety Events (APPRAISE) was a phase 2, double-blind, placebo-controlled, dose-ranging study. Patients (n=1715) with recent ST-elevation or non-ST-elevation acute coronary syndrome were randomized to 6 months of placebo (n=611) or 1 of 4 doses of apixaban: 2.5 mg twice daily (n=317), 10 mg once daily (n=318), 10 mg twice daily (n=248), or 20 mg once daily (n=221). Nearly all patients received aspirin; 76% received clopidogrel. The primary outcome was International Society of Thrombosis and Hemostasis major or clinically relevant nonmajor bleeding. A secondary outcome was cardiovascular death, myocardial infarction, severe recurrent ischemia, or ischemic stroke. At the recommendation of the Data Monitoring Committee, the 2 higher-dose apixaban arms were discontinued because of excess total bleeding. Compared with placebo, apixaban 2.5 mg twice daily (hazard ratio, 1.78; 95% confidence interval, 0.91 to 3.48; P=0.09) and 10 mg once daily (hazard ratio, 2.45; 95% confidence interval, 1.31 to 4.61; P=0.005) resulted in a dose-dependent increase in major or clinically relevant nonmajor bleeding. Apixaban 2.5 mg twice daily (hazard ratio, 0.73; 95% confidence interval, 0.44 to 1.19; P=0.21) and 10 mg once daily (hazard ratio, 0.61; 95% confidence interval, 0.35 to 1.04; P=0.07) resulted in lower rates of ischemic events compared with placebo. The increase in bleeding was more pronounced and the reduction in ischemic events was less evident in patients taking aspirin plus clopidogrel than in those taking aspirin alone. CONCLUSIONS: We observed a dose-related increase in bleeding and a trend toward a reduction in ischemic events with the addition of apixaban to antiplatelet therapy in patients with recent acute coronary syndrome. The safety and efficacy of apixaban may vary depending on background antiplatelet therapy. Further testing of apixaban in patients at risk of recurrent ischemic events is warranted.
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