| 1. |
- Schael, S., et al.
(författare)
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Electroweak measurements in electron positron collisions at W-boson-pair energies at LEP
- 2013
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Ingår i: Physics Reports. - : Elsevier BV. - 0370-1573 .- 1873-6270. ; 532:4, s. 119-244
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Forskningsöversikt (refereegranskat)abstract
- Electroweak measurements performed with data taken at the electron positron collider LEP at CERN from 1995 to 2000 are reported. The combined data set considered in this report corresponds to a total luminosity of about 3 fb(-1) collected by the four LEP experiments ALEPH, DELPHI, 13 and OPAL, at centre-of-mass energies ranging from 130 GeV to 209 GeV. Combining the published results of the four LEP experiments, the measurements include total and differential cross-sections in photon-pair, fermion-pair and four-fermion production, the latter resulting from both double-resonant WW and ZZ production as well as singly resonant production. Total and differential cross-sections are measured precisely, providing a stringent test of the Standard Model at centre-of-mass energies never explored before in electron positron collisions. Final-state interaction effects in four-fermion production, such as those arising from colour reconnection and Bose Einstein correlations between the two W decay systems arising in WW production, are searched for and upper limits on the strength of possible effects are obtained. The data are used to determine fundamental properties of the W boson and the electroweak theory. Among others, the mass and width of the W boson, m(w) and Gamma(w), the branching fraction of W decays to hadrons, B(W -> had), and the trilinear gauge-boson self-couplings g(1)(Z), K-gamma and lambda(gamma), are determined to be: m(w) = 80.376 +/- 0.033 GeV Gamma(w) = 2.195 +/- 0.083 GeV B(W -> had) = 67.41 +/- 0.27% g(1)(Z) = 0.984(-0.020)(+0.018) K-gamma - 0.982 +/- 0.042 lambda(gamma) = 0.022 +/- 0.019. (C) 2013 Elsevier B.V. All rights reserved.
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| 2. |
- 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. |
- Gohritz, A., et al.
(författare)
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Rekonstruktion der aktiven Ellbogenbeugung durch bipolare Transposition des Musculus latissimus dorsi : [Restoration of active elbow flexion by muscle transfer of the latissimus dorsi]
- 2009
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Ingår i: Operative Orthopädie und Traumatologie. - 0934-6694. ; 21:2, s. 115-25
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: Reconstruction of active elbow flexion against gravity (strength grade > or =M(3)) by transfer of the latissimus dorsi muscle in order to improve the functionality of the upper extremity. INDICATIONS: Irreparable lesions of the musculocutaneous nerve (C(5)/6). Failure of regeneration after peripheral nerve reconstruction for the musculocutaneous nerve (neurolysis, suture, nerve grafting). Brachial plexus injury (lesions to the upper part, C(5)/6). Loss of biceps function due to trauma, ischemia, poliomyelitis or tumor. CONTRAINDICATIONS: Possible recovery of biceps function by reinnervation, spontaneously or after nerve reconstruction. Weakness of the latissimus dorsi muscle (strength grade < M(4)). Insufficient passive range of motion of the elbow joint (osteoarthritis, contracture). Lack of motivation, reliability, and cooperation of the patient in postoperative rehabilitation program. SURGICAL TECHNIQUE: The intact latissimus dorsi muscle is transferred with its origin and insertion ventrally and sutured with its thoracic aponeurosis into the insertion of the biceps tendon in order to act as an elbow flexor. POSTOPERATIVE MANAGEMENT: Following postoperative immobilization in an upper-arm Gilchrist bandage at 100 degrees flexion and supination (or neutral position, but not pronation) of the forearm for 6 weeks, passive motion exercises of the elbow are started. Active flexion and extension exercises begin at 8-10 weeks postoperatively. To prevent the deleterious effect of muscle and tendon elongation, an orthosis is used during the night to keep the elbow flexed at 90 degrees for 6 months. RESULTS: According to the authors' experience and the results reported in the literature, bipolar latissimus dorsi muscle transfer is a reliable method to restore functional elbow flexion regarding range of motion (> 90 degrees elbow flexion) and strength (at least antigravity strength, > or =M(3)) with acceptable donor morbidity and complication rate.
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