| 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. |
- Smith, Anderson David, et al.
(författare)
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Graphene-based piezoresistive pressure sensing for uniaxial and biaxial strains
- 2014
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Ingår i: 2014 Silicon Nanoelectronics Workshop, SNW 2014. - : Institute of Electrical and Electronics Engineers (IEEE). - 9781479956777
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Konferensbidrag (refereegranskat)abstract
- The piezoresistive effect in graphene has been experimentally demonstrated for both uniaxial and biaxial strains. For uniaxial strain, rectangular membranes were measured while circular membranes provided biaxial strain. Gauge factors have also been extracted and compared to previous literature as well as simulations.
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| 3. |
- Margittai, M., et al.
(författare)
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Single-molecule fluorescence resonance energy transfer reveals a dynamic equilibrium between closed and open conformations of syntaxin 1
- 2003
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 100:26, s. 15516-15521
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Tidskriftsartikel (refereegranskat)abstract
- Protein conformational transitions form the molecular basis of many cellular processes, such as signal transduction and membrane traffic. However, in many cases, little is known about their structural dynamics. Here we have used dynamic single-molecule fluorescence to study at high time resolution, conformational transitions of syntaxin 1, a soluble N-ethylmaleimide-sensitive factor attachment protein receptors protein essential for exocytotic membrane fusion. Sets of syntaxin double mutants were randomly labeled with a mix of donor and acceptor dye and their fluorescence resonance energy transfer was measured. For each set, all fluorescence information was recorded simultaneously with high time resolution, providing detailed information on distances and dynamics that were used to create structural models. We found that free syntaxin switches between an inactive closed and an active open configuration with a relaxation time of 0.8 ms, explaining why regulatory proteins are needed to arrest the protein in one conformational state.
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| 4. |
- Negm, N., et al.
(författare)
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Graphene waveguide-integrated thermal infrared emitter
- 2022
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Ingår i: Device Research Conference - Conference Digest, DRC. - : Institute of Electrical and Electronics Engineers (IEEE).
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Konferensbidrag (refereegranskat)abstract
- Low-cost and easily integrable mid-infrared (MIR) sources are highly desired for photonic integrated circuits. Thermal incandescent MIR sources are widely used. They work by Joule heating, i.e. an electrical current through the emitter causes thermal emission according to Planck's law. Their simple design with only two contact pads makes them integrable with typical optoelectronic components in high-volume production flows. Graphene's emissivity is comparable to common metallic emitters. In contrast to the latter, graphene is transparent at MIR wavelengths, which enables placing large area graphene emitters in the evanescent field of integrated waveguides [1]-[2]. This enhances emission by near-field coupling directly into the waveguide mode, avoiding the mode-mismatch to free space. Here, we present the first experimental demonstration of a graphene emitter placed directly on a photonic waveguide, hence emitting directly into the waveguide mode.
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