| 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. |
- Aamodt, K., et al.
(författare)
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The ALICE experiment at the CERN LHC
- 2008
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Ingår i: Journal of Instrumentation. - 1748-0221. ; 3:S08002
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Forskningsöversikt (refereegranskat)abstract
- ALICE (A Large Ion Collider Experiment) is a general-purpose, heavy-ion detector at the CERN LHC which focuses on QCD, the strong-interaction sector of the Standard Model. It is designed to address the physics of strongly interacting matter and the quark-gluon plasma at extreme values of energy density and temperature in nucleus-nucleus collisions. Besides running with Pb ions, the physics programme includes collisions with lighter ions, lower energy running and dedicated proton-nucleus runs. ALICE will also take data with proton beams at the top LHC energy to collect reference data for the heavy-ion programme and to address several QCD topics for which ALICE is complementary to the other LHC detectors. The ALICE detector has been built by a collaboration including currently over 1000 physicists and engineers from 105 Institutes in 30 countries, Its overall dimensions are 16 x 16 x 26 m(3) with a total weight of approximately 10 000 t. The experiment consists of 18 different detector systems each with its own specific technology choice and design constraints, driven both by the physics requirements and the experimental conditions expected at LHC. The most stringent design constraint is to cope with the extreme particle multiplicity anticipated in central Pb-Pb collisions. The different subsystems were optimized to provide high-momentum resolution as well as excellent Particle Identification (PID) over a broad range in momentum, up to the highest multiplicities predicted for LHC. This will allow for comprehensive studies of hadrons, electrons, muons, and photons produced in the collision of heavy nuclei. Most detector systems are scheduled to be installed and ready for data taking by mid-2008 when the LHC is scheduled to start operation, with the exception of parts of the Photon Spectrometer (PHOS), Transition Radiation Detector (TRD) and Electro Magnetic Calorimeter (EMCal). These detectors will be completed for the high-luminosity ion run expected in 2010. This paper describes in detail the detector components as installed for the first data taking in the summer of 2008.
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| 3. |
- Ablikim, M., et al.
(författare)
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Measurements of (XcJ)-> K+K-K+K- decays
- 2006
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Ingår i: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 642:3, s. 197-202
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Tidskriftsartikel (refereegranskat)abstract
- Using 14M psi(2S) events taken with the BESII detector, chi(cJ) -> 2(K+K-) decays are studied. For the four-kaon final state, the branching fractions are B(chi(c0,1,2) ->.2(K+K-)) = (3.48 +/- 0.23 +/- 0.47) x 10(-3), (0.70 +/- 0.13 +/- 0.10) x 10(-3), and (2.17 +/- 0.20 +/- 0.31) x 10(-3). For the phi K+K- final state, the branching fractions, which are measured for the first time, are B(chi(c0,1,2) -> phi K+K-) = (1.03 +/- 0.22 +/- 0.15) x 10(-3), (0.46 +/- 0.16 +/- 0.06) x 10(-3), and (1.67 +/- 0.26 +/- 0.24) x 10(-4). For the phi phi final state, B(chi(c0,2) -> phi phi) = (0.94 +/- 0.21 +/- 0.13) x 10(-3) and (1.70 +/- 0.30 +/- 0.25) x 10(-3).
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| 4. |
- Abazov, V. M., et al.
(författare)
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The upgraded DO detector
- 2006
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Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier BV. - 0168-9002 .- 1872-9576. ; 565:2, s. 463-537
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Tidskriftsartikel (refereegranskat)abstract
- The DO experiment enjoyed a very successful data-collection run at the Fermilab Tevatron collider between 1992 and 1996. Since then, the detector has been upgraded to take advantage of improvements to the Tevatron and to enhance its physics capabilities. We describe the new elements of the detector, including the silicon microstrip tracker, central fiber tracker, solenoidal magnet, preshower detectors, forward muon detector, and forward proton detector. The uranium/liquid -argon calorimeters and central muon detector, remaining from Run 1, are discussed briefly. We also present the associated electronics, triggering, and data acquisition systems, along with the design and implementation of software specific to DO.
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| 5. |
- Lu, R, et al.
(författare)
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Genetic associations of LYN with systemic lupus erythematosus
- 2009
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Ingår i: Genes and Immunity. - : Springer Science and Business Media LLC. - 1466-4879 .- 1476-5470. ; 10:5, s. 397-403
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Tidskriftsartikel (refereegranskat)abstract
- We targeted LYN, a src-tyosine kinase involved in B-cell activation, in case-control association studies using populations of European-American, African-American and Korean subjects. Our combined European-derived population, consisting of 2463 independent cases and 3131 unrelated controls, shows significant association with rs6983130 in a female-only analysis with 2254 cases and 2228 controls (P=1.1 x 10(-4), odds ratio (OR)=0.81 (95% confidence interval: 0.73-0.90)). This single nucleotide polymorphism (SNP) is located in the 5' untranslated region within the first intron near the transcription initiation site of LYN. In addition, SNPs upstream of the first exon also show weak and sporadic association in subsets of the total European-American population. Multivariate logistic regression analysis implicates rs6983130 as a protective factor for systemic lupus erythematosus (SLE) susceptibility when anti-dsDNA, anti-chromatin, anti-52 kDa Ro or anti-Sm autoantibody status were used as covariates. Subset analysis of the European-American female cases by American College of Rheumatology classification criteria shows a reduction in the risk of hematological disorder with rs6983130 compared with cases without hematological disorders (P=1.5 x 10(-3), OR=0.75 (95% CI: 0.62-0.89)). None of the 90 SNPs tested show significant association with SLE in the African American or Korean populations. These results support an association of LYN with European-derived individuals with SLE, especially within autoantibody or clinical subsets.
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| 6. |
- Chen, K., et al.
(författare)
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High permittivity in zr doped NiO ceramics
- 2007
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Ingår i: Journal of Applied Physics. - : American Institute of Physics (AIP). - 0021-8979 .- 1089-7550. ; 102:3, s. 034103-
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Tidskriftsartikel (refereegranskat)abstract
- We report on measurements of the dielectric permittivity of NiO-based ceramics doped with Zr (ZNO). Samples were prepared by the traditional solid-state reaction method. The concentration of Zr has an effect on the dielectric properties of ZNO ceramics. High permittivity values (similar to 10(4)) were observed which remain almost constant from 200 K to 350 K at low frequencies. The high-dielectric-constant response of the ZNO ceramics is attributed mainly to a grain boundary (internal) barrier layer capacitance. (c) 2007 American Institute of Physics.
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| 7. |
- Wang, J. H., et al.
(författare)
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Thermodynamic assessment of the Au-Ni system
- 2005
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Ingår i: Calphad. - : Elsevier BV. - 0364-5916 .- 1873-2984. ; 29:4, s. 263-268
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Tidskriftsartikel (refereegranskat)abstract
- The phase diagram and thermodynamic properties of the Au-Ni system have been assessed from experimental thermodynamic and phase diagram data by means of the CALPHAD method. A consistent set of thermodynamic parameters for each phase was obtained. Good agreement is reached between the calculated and experimental results. The calculated congruent point is 1214.3 K and 42.6 at.% Ni and the critical point of the miscibility gap is 1089.5 K and 73.0 at.% Ni.
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| 8. |
- Chen, Q., et al.
(författare)
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Thermodynamic calculation and kinetic simulation related to solidification process
- 2006
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Ingår i: Modeling of Casting, Welding and Advanced Solidification Processes - XI. - 0873396294 - 9780873396295 ; , s. 529-536
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Konferensbidrag (refereegranskat)abstract
- This paper presents a brief review and some new results of the thermodynamic calculation and kinetic simulation related to the micro-modelling of solidification processes by using ThermoCalc and DICTRA. Emphasis is given on a partial-equilibrium approach developed as a modification of the Scheil-Gulliver non-equilibrium approximation to treat effectively the back diffusion of fast diffusing elements in solid phases. We start with a DICTRA simulation and successfully explain why the P peak drifts away from those of Mn and Si in the experimentally observed composition profiles of a carbon steel. Then, for this steel and other 16 carbon and low alloy steels, we perform both non-equilibrium and partial-equilibrium solidification calculations and demonstrate the significant improvement of the partial-equilibrium approach by comparing the freezing range results with those from either DICTRA simulations or experimental observations.
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| 9. |
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| 10. |
- Piber, H., et al.
(författare)
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RILEM Interlaboratory Test on Interlayer Bonding of Asphalt Pavements
- 2009
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Ingår i: ADVANCED TESTING AND CHARACTERISATION OF BITUMINOUS MATERIALS, VOLS 1 AND 2. ; , s. 1181-1189
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Konferensbidrag (refereegranskat)abstract
- The RILEM TG 4 organized an interlaboratory test in order to compare the different test procedures to assess the interlayer bonding properties of asphalt pavement. The pavement was composed of two layers. Three different interface conditions were chosen. The first pavement was laid without interface treatment and the others with two different types of emulsion. 14 laboratories from 11 countries participated in this study and carried out shear or torque tests on 1400 cores. The maximum shear or torque load and the corresponding displacement were measured and the shear or torque stress was calculated as a function of the following parameters: diameter, test temperature, test speed, stress applied normal to the interface and age of the specimen. This paper presents the results of this study in terms of precision and correlations regarding the parameters.
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