| 1. |
- Schael, S, et al.
(author)
-
Precision electroweak measurements on the Z resonance
- 2006
-
In: Physics Reports. - : Elsevier BV. - 0370-1573 .- 1873-6270. ; 427:5-6, s. 257-454
-
Research review (peer-reviewed)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.
|
|
| 2. |
- Göök, A., et al.
(author)
-
Photo-fission at the S-DALINAC
- 2009
-
In: 4th international workshop on nuclear fission and fission-product spectroscopy. - : American Institute of Physics (AIP). - 9780735407145 ; , s. 351-354
-
Conference paper (other academic/artistic)abstract
- Experiments on photo-induced fission of 238U and 234U using bremsstrahlung with endpoint energies between 6 MeV and 9 MeV have been carried out at the superconducting Darmstadt electron linear accelerator S-DALINAC. A twin Frisch grid ionization chamber has been used to determine energy and mass distributions via the 2E-technique. The fission fragment emission angle, which is used to correct for energy loss in the target and backing material for a correct determination of fragment energy and mass, is deduced from the time difference between cathode and anode signals. The research program including the foreseen search for parity violation in photo-induced fission and first experimental results will be presented. © 2009 American Institute of Physics.
|
|
| 3. |
|
|
| 4. |
- Neumann, JO, et al.
(author)
-
The use of hyperventilation theraphy after traumatic brain injury in Europe : an analysis of the BrainIT database
- 2008
-
In: Intensive Care Medicine. - : Springer Science and Business Media LLC. - 0342-4642 .- 1432-1238. ; 34:9, s. 1676-1682
-
Journal article (peer-reviewed)abstract
- Objective To assess the use of hyperventilation and the adherence to Brain Trauma Foundation-Guidelines (BTF-G) after traumatic brain injury (TBI). Setting Twenty-two European centers are participating in the BrainIT initiative. Design Retrospective analysis of monitoring data. Patients and participants One hundred and fifty-one patients with a known time of trauma and at least one recorded arterial blood–gas (ABG) analysis. Measurements and results A total number of 7,703 ABGs, representing 2,269 ventilation episodes(VE) were included in the analysis. Related minute-by-minute ICP data were taken from a 30 min time window around each ABG collection. Data are given as mean with standard deviation. (1) Patients without elevated intracranial pressure (ICP) (\20 mmHg) manifested a statistically significant higher PaCO2(36 ± 5.7 mmHg) in comparison to patients with elevated ICP(C20 mmHg; PaCO2:34 ± 5.4 mmHg, P\0.001). (2) Intensified forced hyperventilation(PaCO2 B 25 mmHg) in the absence of elevated ICP was found in only 49VE (2%). (3) Early prophylactic hyperventilation (\24 h after TBI;PaCO2 B 35 mmHg,ICP\20 mmHg) was used in 1,224VE (54%). (4) During forced hyperventilation(PaCO2 B 30 mmHg), simultaneous monitoring of brain tissue pO2 or SjvO2 was used in only 204 VE (9%). Conclusion While overall adherence to current BTF-Gseems to be the rule, its recommendations on early prophylactic hyperventilation as well as the use of additional cerebral oxygenation monitoring during forced hyperventilation are not followed in this sample of European TBI centers. Descriptor Neurotrauma
|
|
| 5. |
- Boukhvalov, D. W., et al.
(author)
-
Electronic structure of a Mn-12 molecular magnet : Theory and experiment
- 2007
-
In: Physical Review B. Condensed Matter and Materials Physics. - 1098-0121 .- 1550-235X. ; 75:1, s. 014419-
-
Journal article (peer-reviewed)abstract
- We used site-selective and element-specific resonant inelastic x-ray scattering (RIXS) to study the electronic structure and the electron interaction effects in the molecular magnet [Mn12O12(CH3COO)(16)(H2O)(4)]center dot 2CH(3)COOH center dot 4H(2)O, and compared the experimental data with the results of local spin density approximation +U electron structure calculations which include the on-site Coulomb interactions. We found a good agreement between theory and experiment for the Coulomb repulsion parameter U = 4 eV. In particular, the p-d band separation of 1.8 eV has been found from the RIXS spectra, which is in accordance with the calculations. Similarly, the positions of the peaks in the XPS spectra agree with the calculated densities of p and d states. Using the results of the electronic structure calculations, we determined the intramolecular exchange parameters, and used them for diagonalization of the Mn-12 spin Hamiltonian. The calculated exchanges gave the correct ground state with the total spin S = 10.
|
|
| 6. |
- Enders, J, et al.
(author)
-
Electric dipole strength below the giant dipole resonance
- 2005
-
In: Acta Physica Polonica. Series B: Elementary Particle Physics, Nuclear Physics, Statistical Physics, Theory of Relativity, Field Theory. - 0587-4254. ; 36:4, s. 1077-1087
-
Journal article (peer-reviewed)abstract
- Recent experimental findings and theoretical approaches to the electric dipole (El) strength distribution below the particle emission threshold at shell closures are revisited. Results from photon scattering experiments are discussed and compared to predictions within the quasiparticle-phonon nuclear model. An analysis of the fine structure of the El strength is presented. Recent studies of the E1 response of light exotic nuclei are also discussed.
|
|
| 7. |
|
|
| 8. |
- Kazmierczak, Karolina, et al.
(author)
-
Observer reliability of industrial activity analysis based on video recordings
- 2006
-
In: International Journal of Industrial Ergonomics. - : Elsevier BV. - 0169-8141 .- 1872-8219. ; 36:3, s. 275-282
-
Journal article (peer-reviewed)abstract
- The aim of this study was to assess the agreement between observers analyzing activity patterns during truck engine assembly work based on video recordings. Two observers observed the recordings of nine workers, on the average 2.2 h long, assigning activities to four activity categories. For each activity category data were obtained on the mean duration of uninterrupted sequences of activities and their relative time proportion in the job. This data was analyzed with 2-way crossed ANOVA algorithms to derive the components of variance attributed to disagreement between observers, to differences between filmed subjects, and to residual "unexplained" variance. The latter was interpreted as an estimate of within-observer variability and possible interactions between subject and observer. While the observers disagreed about the overall time proportions for the four activity categories by no more than 3.7% of time, their second-to-second classification disagreed for 13% of the total analysis time. The between-observer variance was small as compared to within-observer variance and the variance between Subjects performing the same job. Simulations based oil the variance components showed that a group mean of the proportion of direct work could be determined with a standard deviation within 5% of the mean by having two observers analyzing one 2-h video recording once, each. Relevance to industry The results of this study may support decision making when designing a reliable video-based analysis of industrial work. Thus, the study helps production engineers, ergonomics practitioners and researchers allocate resources between data collection and data analysis, based on their preferences for precision and power of a particular study. (c) 2006 Elsevier B.V. All rights reserved.
|
|
| 9. |
|
|
| 10. |
- Neumann, Oara, et al.
(author)
-
Direct optical detection of aptamer conformational changes induced by target molecules
- 2009
-
In: Analytical chemistry. - : ACS Publications. - 1520-6882 .- 0003-2700. ; 81:24, s. 10002-6
-
Journal article (peer-reviewed)abstract
- Aptamers are single-stranded DNA/RNA oligomers that fold into three-dimensional conformations in the presence of specific molecular targets. Surface-enhanced Raman spectroscopy (SERS) of thiol-bound DNA aptamer self-assembled monolayers on Au nanoshell surfaces provides a direct, label-free detection method for the interaction of DNA aptamers with target molecules. A spectral cross-correlation function, Gamma, is shown to be a useful metric to quantify complex changes in the SERS spectra resulting from conformational changes in the aptamer induced by target analytes. While the pristine, unexposed anti-PDGF (PDGF = platelet-derived growth factor) aptamer yields highly reproducible spectra with Gamma = 0.91 +/- 0.01, following incubation with PDGF, the reproducibility of the SERS spectra is dramatically reduced, yielding Gamma = 0.67 +/- 0.02. This approach also allows us to discriminate the response of a cocaine aptamer to its target from its weaker response to nonspecific analyte molecules.
|
|
