1,674 research outputs found
Influence of the nucleon spectral function in photon and electron induced reactions on nuclei
We study the influence of the nucleon spectral function on eta photo- and
electroproduction on nuclei. Besides kinematical effects due to groundstate
correlations, also a modification of the S11(1535) decay width is taken into
account, which is caused by the possible decay into nucleons with mass smaller
than the pole mass in the medium. Hence, resonances with masses below the free
N eta threshold can contribute to eta production.Comment: 13 pages, 8 figure
Correlations in hypernuclear matter
We investigate short range correlations in nuclear and hypernuclear matter.
Self-energies due to short range correlations and their influence on the
nucleon and -hyperon spectral functions are described in an approach
accounting for a realistic treatment of mean-field dynamics and a
self-consistently derived quasi-particle interaction. Landau-Migdal theory is
used to derived the short range interaction from a phenomenological Skyrme
energy density functional, subtracting the long range pionic contributions to
the nucleonic spectral functions. We discuss our results for different
hyperon-baryon ratios to show the influence of strangeness on the correlations
in hypernuclear matter.Comment: 7 pages, 5 figures, proceedings for HYP06 in Main
Investigation of continental drift, phase 1 effort Progress report, 1 Apr. - 30 Sep. 1968
Feasibility of using ultrashort pulse laser ranging and independent clock radio interferometry distance measurement methods to test for existence of continental drif
Transport study of charged current interactions in neutrino-nucleus reactions
Within a dynamical transport approach we investigate charged current
interactions in neutrino-nucleus reactions for neutrino energies of 0.3 - 1.5
GeV with particular emphasis on resonant pion production channels via the
resonance. The final-state-interactions of the resonance as
well as of the emitted pions are calculated explicitly for and
nuclei and show a dominance of pion suppression at moderate momenta
0.2 GeV/c. A comparison to integrated spectra for reactions with the available (preliminary) data demonstrates a
reasonable agreement.Comment: 13 pages incl. 6 eps-figures; computational error in final state
interactions corrected; to be published in Phys. Lett.
The procurement and evaluation of a prototype laser satellite-tracking system Final report, 1 Jan. 1967 - 30 Sep. 1968
Pulsed ruby laser satellite tracking syste
Photographic measurements of the energy distribution in the beam of a ruby laser
Photographic measurement of energy distribution in beam of Q-switched ruby lase
Photoproduction of pi0-mesons from nuclei
Photoproduction of neutral pions from nuclei (carbon, calcium, niobium, lead)
has been studied for incident photon energies from 200 MeV to 800 MeV with the
TAPS detector using the Glasgow photon tagging spectrometer at the Mainz MAMI
accelerator. Data were obtained for the inclusive photoproduction of neutral
pions and the partial channels of quasifree single pi0, double pi0, and
pi0pi+/- photoproduction. They have been analyzed in terms of the in-medium
behavior of nucleon resonances and the pion - nucleus interaction. They are
compared to earlier measurements from the deuteron and to the predictions of a
Boltzmann-Uehling-Uhlenbeck (BUU) transport model for photon induced pion
production from nuclei.Comment: 15 pages, 22 figures, accepted for publication in EPJ
Measurements of satellite range with a ruby laser
Range measurements of GEOS-I and BE-C satellites with ruby lase
Use of a laser for satellite-range measurement
Optical laser satellite range measuring syste
Vanadium centers in ZnTe crystals. II. Electron paramagnetic resonance
Four V-related electron-paramagnetic-resonance (EPR) spectra are observed in Bridgman-grown ZnTe doped with vanadium. Two of them are attributed to the charge states VZn3+(A+) and VZn2+(A0) of the isolated V impurity. For the ionized donor, VZn3+(A+), the spectrum reveals the typical behavior of the expected 3A2(F) ground state in tetrahedral symmetry. The incorporation on a cation lattice site could be proved by the resolved superhyperfine interaction with four Te ions. The second spectrum showing triclinic symmetry and S=3/2 is interpreted as the neutral donor state VZn2+(A0). The origin of the triclinic distortion of the cubic (Td) crystal field could be a static Jahn-Teller effect. The two additionally observed EPR spectra are attributed to nearest-neighbor V-related defect pairs. The spectrum of the first one, V2+Zn-YTe, shows trigonal symmetry and can be explained by the S=3/2 manifold of an orbital singlet ground state. An associated defect "YTe" is responsible for the trigonal distortion of the tetrahedral crystal field of V2+Zn. The spectrum of the second pair defect also shows trigonal symmetry and can be described by S=1/2. The ground-state manifold implies a VZn3+−XTe pair as the most probable origin of this spectrum. The S=1/2 ground state is produced by a dominating isotropic exchange interaction coupling the S=1 ground-state manifold of V3+Zn to an assumed S=1/2 ground state of "XTe" in antiferromagnetic orientation. The nature of the associated defects "YTe" and "XTe" remains unknown for both pairs since no hyperfine structure has been observed, but most probably acceptorlike defects are involved
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