4,761 research outputs found
On the decay of deformed actinide nuclei
decay through a deformed potential barrier produces significant
mixing of angular momenta when mapped from the nuclear interior to the outside.
Using experimental branching ratios and either semi-classical or
coupled-channels transmission matrices, we have found that there is a set of
internal amplitudes which are essentially constant for all even--even actinide
nuclei. These same amplitudes also give good results for the known anisotropic
particle emission of the favored decays of odd nuclei in the same mass
region.
PACS numbers: 23.60.+e, 24.10.Eq, 27.90.+bComment: 5 pages, latex (revtex style), 2 embedded postscript figures
uuencoded gz-compressed .tar file To appear in Physical Review Letter
Applying a framework for critical reflection in educational psychology practice: views of trainee educational psychologists
A framework to support critical reflection in educational psychology (EP) practice is described. The process of critical reflection and the underlying theoretical ideas are discussed, including the links between critical reflection and action for social justice change in EP work. The article reports on a participatory research project with trainee educational psychologists on their experiences of using the framework in practice. Four focus groups were held involving 16 co-researchers; the videos of the focus groups were analysed using a thematic analysis approach by the co-researchers themselves. Themes identified relating to their experience of using the framework are: âpositive experienceâ, âflexible applicationâ, âfacilitating deeper thinkingâ, âinfluence of self (reflexivity)â. Themes relating to co-researcher views on how the framework can be developed are related to accessibility and usability. The article concludes with implications of the research for use and development of the framework and for critically reflective EP training and practice
Do Solar Neutrino Experiments Imply New Physics?
None of the 1000 solar models in a full Monte Carlo simulation is consistent
with the results of the chlorine or the Kamiokande experiments. Even if the
solar models are forced artifically to have a \b8 neutrino flux in agreeement
with the Kamiokande experiment, none of the fudged models agrees with the
chlorine observations. The GALLEX and SAGE experiments, which currently have
large statistical uncertainties, differ from the predictions of the standard
solar model by and , respectively.Comment: 7 pages (figures not included), Institute for Advanced Study number
AST 92/51. For a hard copy with the figures, write: [email protected]
Fusion barrier distributions in systems with finite excitation energy
Eigen-channel approach to heavy-ion fusion reactions is exact only when the
excitation energy of the intrinsic motion is zero. In order to take into
account effects of finite excitation energy, we introduce an energy dependence
to weight factors in the eigen-channel approximation. Using two channel
problem, we show that the weight factors are slowly changing functions of
incident energy. This suggests that the concept of the fusion barrier
distribution still holds to a good approximation even when the excitation
energy of the intrinsic motion is finite. A transition to the adiabatic
tunneling, where the coupling leads to a static potential renormalization, is
also discussed.Comment: 9 pages, 4 figures, Submitted to Physical Review
Use of domesticated pigs by Mesolithic hunter-gatherers in northwestern Europe
Acknowledgements We thank the Archaeological State Museum Schleswig-Holstein, the Archaeological State Offices of Brandenburg, Lower Saxony and Saxony and the following individuals who provided sample material: Betty Arndt, Jo¨rg Ewersen, Frederick Feulner, Susanne Hanik, Ru¨diger Krause, Jochen Reinhard, Uwe Reuter, Karl-Heinz Ro¨hrig, Maguerita Scha¨fer, Jo¨rg Schibler, Reinhold Schoon, Regina Smolnik, Thomas Terberger and Ingrid Ulbricht. We are grateful to Ulrich Schmo¨lcke, Michael Forster, Peter Forster and Aikaterini Glykou for their support and comments on the manuscript. We also thank many institutions and individuals that provided sample material and access to collections, especially the curators of the Museum fu¨r Naturkunde, Berlin; Muse´um National d0 Histoire Naturelle, Paris; Smithsonian Institution, National Museum of Natural History, Washington D.C.; Zoologische Staatssammlung, Mu¨nchen; Museum fu¨r Haustierkunde, Halle; the American Museum of Natural History, New-York. This work was funded by the Graduate School âHuman Development in Landscapesâ at Kiel University (CAU) and supported by NERC project Grant NE/F003382/1. Radiocarbon dating was carried out at the Leibniz Laboratory, CAU. This work is licensed under a Creative Commons AttributionNonCommercial-NoDerivs 3.0 Unported License.Peer reviewedPublisher PD
Neutrino conversions in random magnetic fields and from the Sun
The magnetic field in the convective zone of the Sun has a random small-scale
component with the r.m.s. value substantially exceeding the strength of a
regular large-scale field. For two Majorana neutrino flavors two
helicities in the presence of a neutrino transition magnetic moment and nonzero
neutrino mixing we analyze the displacement of the allowed ()-parameter region reconciled for the SuperKamiokande(SK) and
radiochemical (GALLEX, SAGE, Homestake) experiments in dependence on the r.m.s.
magnetic field value , or more precisely, on a value assuming the
transition magnetic moment . In contrast to RSFP in
regular magnetic fields we find an effective production of electron
antineutrinos in the Sun even for small neutrino mixing through cascade
conversions , in a random magnetic field that would be a
signature of the Majorana nature of neutrino if will be
registered. Basing on the present SK bound on electron antineutrinos we have
also found an excluded area in the same -plane and
revealed a strong sensitivity to the random magnetic field correlation length
.Comment: LaTex 36 pages including 14 PostScript figure
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