| 1. |
- Hamamoto, Ikuko, et al.
(author)
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Form-factor of low-lying Kπ=1+ excitations in rare-earth nuclei
- 1987
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In: Physics Letters B. - : Elsevier BV. - 0370-2693. ; 194:1, s. 6-10
-
Journal article (peer-reviewed)abstract
- The differential cross section of inelastic electron scattering for the low-lying “collective” Kπ=1+ excitations in rare-earth nuclei is calculated in DWBA by using microscopically calculated transition-densities. In the region of low-momentum transfer (q⪅0.5 fm-1) in which experimental data are available the shape of calcualted cross sections is almost the same for all nuclei and is slightly but systematically different from the observed shape.
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| 2. |
- Adiels, Lars, et al.
(author)
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A π0 and η spectrometer of lead glass and BGO for momenta up to 1 GeV/c
- 1986
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In: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier BV. - 0168-9002 .- 1872-9576. ; 244:3, s. 380-390
-
Journal article (peer-reviewed)abstract
- A spectrometer consisting of two sets of bismuth germanium oxide (BGO) crystals and a lead-glass array has been used to measure the [pi]0 and [eta] momentum spectra produced from proton-antiproton annihilations at rest. We describe the test of the BGO sets in electron beams of energies from 50 to 450 MeV. We discuss the method of construction and calibration of the lead-glass array, as well as procedures to extract the energy and position resolutions for detected photons. A momentum resolution ([sigma]) for [pi]0’s and [eta]’s of 4% and 3%, respectively has been achieved at momenta below 1 GeV/c.
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| 3. |
- Adiels, L, et al.
(author)
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Some results of experiment PS182 at LEAR
- 1986
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In: Antiproton 86. - Singspore : World Scientific Publishing. - 9971503131 ; , s. 199-204, s. 199-204
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Conference paper (other academic/artistic)
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| 4. |
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| 5. |
- Mårtensson-Pendrill, Ann-Marie, 1952
(author)
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Calculation of a P-and T-nonconserving weak interaction in Xe and Hg with many-body perturbation theory
- 1985
-
In: Physical Review Letters. - 1079-7114 .- 0031-9007. ; 54:11, s. 1153-
-
Journal article (peer-reviewed)abstract
- The electronic part of a possible P- and T-nonconserving neutral-weak-current-induced electric dipole moment in atomic Xe and Hg was calculated with many-body perturbation theory. After the effects of this P- and T-nonconserving interaction on all core orbitals were treated self-consistently, thereby including all single-particle effects to all orders but no correlation effects, the results μe=(5.2×10−23e m)CTσN and μe=−(6.0×10−22e m)CTσN, respectively, were obtained for Xe and Hg. The value for Xe can be combined with the recent experimental result, ∣∣μe(Xe129)∣∣
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| 6. |
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| 7. |
- Bovin, JO, et al.
(author)
-
Imaging of atomic clouds outside the surfaces of gold crystals by electron microscopy
- 1985
-
In: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 317, s. 47-49
-
Journal article (peer-reviewed)abstract
- The structure of small metal crystals has been intensively examined by high-resolution electron microscopy (HREM). In particular, multiply-twinned gold and silver crystals have been characterized using the profile-imaging method1,2 at atomic resolution, and reconstructed metal surfaces observed2. Crystal structure images of large gold clusters consisting of 55 gold atoms arranged in a cubeoctahedron have been recorded3 using 2.5 Å resolution, and crystal growth, row by row, on a {111} surface has been documented4 using a low-light-level silicon-intensified target television (TV) camera and video system with an on-line image processor. Direct imaging of rearrangements of atomic columns on extended gold surface5 established that profile imaging can provide information about surface self-diffusion. The motion of surface atoms, recorded with a real-time video tape-recorder (VTR) system, and the formation of surface atom steps on {100} surfaces, although not {111}, has also been reported recently6. Dynamic HREM observations at TV rate showing defect motion in gold7 and CdTe (refs. 8, 9) has given information on ‘in-lattice’ rearrangements of columns of atoms. We report here surface profile images recorded with the electron beam along the 〈110〉 direction with spatial resolution of ∼2.0 Å which reveal changes in occupancy of the atom columns often within periods of less than 0.1 s. Surfaces with several adjacent atom columns involved in rapid structural changes frequently interacted with a cloud of atoms extending out to 9 Å off the crystal and changes in shape and density of the clouds were recorded. Although these clouds have already been described6,10, the present work is the first to analyse these events properly and to describe them in detail. The motion of atomic columns and the existence of atom clouds revealed here may have important consequences for crystal growth, surface science and catalysis studies.
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| 8. |
- Wallenberg, LR, et al.
(author)
-
On the crystal structure of small gold crystals and large gold clusters
- 1985
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In: Surface Science. - : Elsevier BV. - 0039-6028. ; 156:1, s. 256-264
-
Journal article (peer-reviewed)abstract
- A large gold cluster with the formula Au55[(C6H5)3P]12Cl6, was imaged with a high-resolution transmission electron microscope (HRTEM) and a proposed model was confirmed. Growth of gold crystals of approximately 4.0 nm size could be followed, row by row of atoms, with the use of a low light level TV camera and on-line image processing.
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| 9. |
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| 10. |
- Adiels, Lars, et al.
(author)
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Experimental study of the inclusive η-spectrum from proton-antiproton annihilations at rest in liquid hydrogen
- 1989
-
In: Zeitschrift für Physik C Particles and Fields. - 0170-9739 .- 1431-5858. ; 42, s. 49-58
-
Journal article (peer-reviewed)abstract
- The inclusive η-momentum spectrum from Mathematical expression annihilations at rest in liquid hydrogen was measured at LEAR. Branching ratios were obtained for Mathematical expression, and ηη(8.1±3.1)×10-5. An upper limit for Mathematical expression of 1.8×10-4 at 95% CL was found. The ratio of the branching ratios is BR(ηÏvariant)/BR(ηω)=0.51-0.06+0.20. For the ratio of branching ratios into two pseudoscalar mesons, we have BR(ηπ0)/BR(Ï€0Ï€0)=0.65±0.14, BR(ηη)/BR(Ï€0Ï€0), BR(ηη′)/BR(Ï€0Ï€0) at 95% CL, and BR(ηη)/BR(ηπ0). © 1989 Springer-Verlag.
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| 11. |
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| 12. |
- Adiels, L, et al.
(author)
-
π0 and η spectroscopy at LEAR
- 1985
-
In: Physics with antiprotons at LEAR in the ACOL era. - Gif sur Yvette : Editions Frontières. - 2863320351 ; , s. 359-360
-
Conference paper (other academic/artistic)
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| 13. |
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| 14. |
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| 15. |
- Aleksandrovski, A. N., et al.
(author)
-
Anomalies of the plastic deformation of solid parahydrogen
- 1987
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In: Soviet Journal of Low Temperature Physics. - 0360-0335. ; 13:10, s. 623-624
-
Journal article (peer-reviewed)abstract
- The work hardening curves σ(ε) of special-purity parahydrogen single crystals are obtained in the temperature range 2-6 °K at very low stresses (σ=5 10 - 2 g/mm2). Our study reveals a number of anomalies, in particular an effect whereby a sample recovers its dimensions after plastic deformation reaching 7%. The work hardening curves of solid neon are also obtained for comparison. The gravity-induced downward flow of parahydrogen single crystals at helium temperatures mentioned in the literature has not been observed.
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| 16. |
- Aleksandrovskii, A. N., et al.
(author)
-
Thermal expansion of solid parahydrogen at helium temperatures
- 1989
-
In: Soviet Journal of Low Temperature Physics. - 0360-0335. ; 15:8, s. 492-493
-
Journal article (peer-reviewed)abstract
- Thermal expansion of solid parahydrogen is investigated in the temperature range from 0.9 to 5 K. The content of the orthomodification in parahydrogen is 0.13 at. %, and that of nonhydrogen impurities is less than 2 10 - 3 at. %. No anisotropy in thermal expansion was observed within the experimental error. The temperature dependence of the linear expansion coefficient can be described by the expression α=1.82 10 - 7 T3. The obtained values of α are in good agreement with the available data on compressibility and ([partial derivate]p/[partial derivate]T)V. The Grüneisen coefficient is γ=3αV/CV`T=2.00 ± 0.25.
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| 17. |
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| 18. |
- Alverson, George, et al.
(author)
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Experimental Search for W / Z Pairs and Higgs Bosons at Very High-Energy Hadron Hadron Colliders
- 1986
-
In: Physics of the Superconducting Supercollider: Proceedings, 1986 Summer Study. ; C860623
-
Conference paper (other academic/artistic)abstract
- We study, from an experimental point of view, the main ways to detect standard high mass Higgs bosons (from 300 Gev up to about 1 TeV) when they decay into W- and Z- pairs at the SSC. We also consider the corresponding W- and Z”-pair continuum which may itself provide interesting physics, and we pay some attention to the case of an intermediate mass charged Higgs decaying into rvr, (met =300 GeV). We first explain why and how high energy pp colliders may search for Higgs’ and we compare their possible performances to those of the e+e- and ep colliders at all possible m-s scale (from few tens of GeV’s up to 1 TeV). We then estimate the rates of the signals and the main backgrounds. Wede5ne the main characteristics of these events as reproduced by M.C. generators (especially implemented with these processes) and simulated through an idealiied In fine-grained calorimeter. A trigger strategy for W- and Z-pairs is derived from this study.
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| 19. |
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| 20. |
- Ambjørn, J., et al.
(author)
-
Langevin simulations of configurations with static charges
- 1985
-
In: Physics Letters B. - 0370-2693. ; 159:4-6, s. 335-340
-
Journal article (peer-reviewed)abstract
- By using the Langevin equation with complex action it is possible to generate (complex) configurations in the charged sector of gauge theories. We test the algorithm in the case of two-dimensional U(1) gauge theory and are able to measure the string tension with great precision and modest use of computer time for a separation of the charged particles where a conventional Wilson loop would have a value ≈ 10-10.
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| 21. |
- Ambjørn, J., et al.
(author)
-
Observation of a string in three-dimensional SU(2) lattice gauge theory
- 1984
-
In: Physics Letters B. - : Elsevier BV. - 0370-2693. ; 142:5-6, s. 410-414
-
Journal article (peer-reviewed)abstract
- SU(2) lattice gauge theory in three dimensions is investigated on a 162×32 lattice. We find that R>×T Wilson loops are well described by a simple string theory for β in the (approximate) scaling region.
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| 22. |
- Ambjørn, J., et al.
(author)
-
Three-dimensional lattice gauge theory and strings
- 1984
-
In: Nuclear Physics, Section B. - : Elsevier BV. - 0550-3213. ; 244:1, s. 262-276
-
Journal article (peer-reviewed)abstract
- We consider SU(2) lattice gauge theory in three dimensions. The Wilson loops are found to be well described by a simple string model in the approximate scaling region.
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| 23. |
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| 24. |
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| 25. |
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| 26. |
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| 27. |
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| 28. |
- Andersson, Bo, et al.
(author)
-
Coherence Effects in Deep Inelastic Scattering
- 1989
-
In: Zeitschrift für Physik C Particles and Fields. - 0170-9739. ; 43:4, s. 625-632
-
Journal article (peer-reviewed)abstract
- We present a framework for deep inelastic scattering, with bound state properties in accordance with a QCD force field acting like a vortex line in a colour superconducting vacuum, which implies some simple coherence effects. Within this scheme one may describe the results of present energies very well, but one obtains an appreciable depletion of gluon radiation in the HERA energy regime.
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| 29. |
- Andersson, Bo, et al.
(author)
-
ON HIGH-ENERGY LEPTOPRODUCTION
- 1981
-
In: Zeitschrift für Physik C Particles and Fields. - 0170-9739. ; C9, s. 233-233
-
Journal article (peer-reviewed)
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| 30. |
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| 31. |
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| 32. |
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| 33. |
- Andersson, L.C., et al.
(author)
-
Lineament mapping in Northern Sweden from Landsat images using orthogonal image transforms
- 1980
-
In: Sixth Annual Symposium Machine Processing of Remotely Sensed Data and Soil Information Systems and Remote Sensing and Soil Survey, June 3 - 6, 1980, Purdue Univ., Laboratory for Applications of Remote Sensing, West Lafayette, Ind. - New York : IEEE Communications Society. ; , s. 147-157
-
Conference paper (peer-reviewed)abstract
- The emphasis of this paper is put on mapping of geological linear structures, and in particular the correlation between these structures orientation and geological or geophysical data. It is also the intention of the authors to present a method to map these structures more objectively than up to now
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| 34. |
- Andersson, L.C., et al.
(author)
-
Lineaments analysis using global and local Fourier transforms
- 1983
-
In: Proceedings of the fourth international conference on basement tectonics, Oslo, Norway, August 10-14, 1981. - Salt Lake City : International Basement Tectonics Association. - 0916347001 ; , s. 63-69
-
Conference paper (peer-reviewed)
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| 35. |
- Andersson, Åke, et al.
(author)
-
Positron production for ESRF
- 1988
-
In: Nuclear Instruments & Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors, and Associated Equipment. - : Elsevier BV. - 0167-5087 .- 0168-9002. ; 267:1, s. 15-21
-
Journal article (peer-reviewed)abstract
- In this report, we first discuss some different pre-injector possibilities for the ESRF booster synchrotron, using estimated machine performances. We then focus on the commercially available linac schemes carrying out more detailed calculations. We also look into the possibility of recyling the particles through the linacs.
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| 36. |
- Ashman, J, et al.
(author)
-
Exclusive ρ0 and Φ production in deep inelastic muon scattering
- 1988
-
In: Zeitschrift für Physik C Particles and Fields. - New York, USA : Springer. - 0170-9739 .- 1431-5858. ; 39:2, s. 169-175
-
Journal article (peer-reviewed)abstract
- Data are presented on exclusive ρ0 and φ{symbol} production in deep inelastic muon scattering from a target consisting mainly of nitrogen. The ratio of the total cross sections for ρ0 and φ{symbol} production is found to be 9:(1.6±0.4) at 〈Q2〉=7.5 GeV2, consistent with the SU(3) prediction of 9:2. The t dependence for exclusive ρ0 production is found to become shallover as Q2 increases and, for large Q2, the t dependence is typical of that for a hard scattering process. Furthermore, the ratio of the cross sections for coherent: incoherent production from nitrogen is found to decrease rapidly with Q2. Such behaviour indicates that even for exclusive vector meson production the virtual photon behaves predominantly as an electromagnetic probe.
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| 37. |
- Asking, Lars, et al.
(author)
-
An electrostatic aerosol sampler
- 1988
-
In: Journal of Aerosol Science. - : Elsevier BV. - 0021-8502. ; 19:7, s. 1023-1026
-
Journal article (peer-reviewed)
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| 38. |
- Axelsson, H., et al.
(author)
-
Candidates for Electron-Neutrino Mass Measurements - the Case of Kr-81
- 1988
-
In: Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics. - : Elsevier BV. - 0370-2693. ; 210:1-2, s. 249-252
-
Journal article (peer-reviewed)abstract
- The nuclear data of the known candidates for neutrino mass determination by resonant electron-capture beta decay are reviewed. New results are presented for the isotope 81Kr, where the transition to the 276 keV state has been found to have QEC=4.7±0.5 keV and a branching ratio of (3.0±0.2)×10−3
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| 39. |
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| 40. |
- Backlund, Y., et al.
(author)
-
Micromachining of Silicon for Thermal and Position-Sensitive Nuclear-Detector Applications
- 1989
-
In: Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. - : Elsevier BV. - 0168-9002. ; 279:3, s. 555-559
-
Journal article (peer-reviewed)abstract
- As part of a programme aiming at the development of small nuclear radiation detectors, for example thermal detectors and position sensitive mosaic structures of surface barrier type, a technique for micromachining the detector bodies in silicon has been developed. The technique is based on an anisotropic etching property of a solution, mainly consisting of KOH. The etch rate is strongly orientation dependent with a speed in the 〈100〉 direction about 400 times faster than in the 〈111〉 direction. The major steps in the etching procedure are described and some examples of deep etching in Si are shown.
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| 41. |
- Bambah, B., et al.
(author)
-
QCD GENERATORS FOR LEP
- 1989
-
In: LEP Physics Workshop Geneva, Switzerland, February 20, 1989. ; , s. 143-340
-
Conference paper (other academic/artistic)
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| 42. |
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| 43. |
- Bengtsson, Hans-Uno, et al.
(author)
-
PYTHIA: THE LUND MONTE CARLO FOR HADRONIC PROCESSES
- 1986
-
In: Physics of the Superconducting Supercollider: Proceedings, 1986 Summer Study, June 23 - July 11, 1986, Snowmass, Colorado. ; C860623, s. 311-311
-
Conference paper (other academic/artistic)
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| 44. |
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| 45. |
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| 46. |
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| 47. |
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| 48. |
- Bengtsson, Mats, et al.
(author)
-
Parton Showers in Leptoproduction Events
- 1988
-
In: Zeitschrift für Physik C Particles and Fields. - 0170-9739. ; 37:3, s. 465-476
-
Journal article (peer-reviewed)abstract
- We present a model that includes the production of arbitrarily many jets in lepton-hadron events, using the leading log formalism for parton shower evolution. The main problem encountered here, which has not previously been illuminated by studies ofe+e− annihilation or Drell-Yan/Z0/W± production, is the choice of kinematics in the space-like shower evolution. In our preferred solution, the standard definition of Bjorkenx is preserved during the construction of initial and final state showers—a nontrivial constraint. The resulting model is described in detail, including some first investigations of its properties.
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| 49. |
- Bengtsson, Mats, et al.
(author)
-
QCD effects on the event structure in leptoproduction
- 1988
-
In: Nuclear Physics, Section B. - : Elsevier BV. - 0550-3213. ; 301:4, s. 554-582
-
Journal article (peer-reviewed)abstract
- Perturbative QCD corrections to leptoproduction events can be introduced either in the form of matrix elements or of parton showers. Each of these approaches has its advantages and disadvantages, making a comparison of the two interesting. At present energies, both methods can be made to agree reasonably well with data, whereas differences appear at higher energies. The influence of these QCD effects on the expected event structure at ep colliders, HERA in particular, is investigated in detail. This includes multiplicity and momentum distributions, transverse momentum flow and correlations, as well as jet properties.
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| 50. |
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