147,239 research outputs found
The Al Gamma-ray Line from Massive-Star Regions
The measurement of gamma rays from the diffuse afterglow of radioactivity
originating in massive-star nucleosynthesis is considered a laboratory for
testing models, when specific stellar groups are investigated, at known
distance and with well-constrained stellar population. Regions which have been
exploited for such studies include Cygnus, Carina, Orion, and
Scorpius-Centaurus. The Orion region hosts the Orion OB1 association and its
subgroups at about 450~pc distance. We report the detection of Al gamma
rays from this region with INTEGRAL/SPI.Comment: Contribution to Symposium "Nuclei in the Cosmos XIV", Niigata, Japan,
Jun 2016; 3 pages, 2 figures; accepted for publication in JPS (Japan Physical
Society) Conference Proceedings http://jpscp.jps.jp
Tensor interaction contributions to single-particle energies
We calculate the contribution of the nucleon-nucleon tensor interaction to
single-particle energies with finite-range matrix potentials and with
zero-range Skyrme potentials. The Skx Skyrme parameters including the
zero-range tensor terms with strengths calibrated to the finite-range results
are refitted to nuclear properties. The fit allows the zero-range
proton-neutron tensor interaction as calibrated to the finite-range potential
results and that gives the observed change in the single-particle gap
(h)-(g) going from Sn to
Sn. However, the experimental dependence of the spin-orbit
splittings in Sn and Pb is not well described when the tensor
is added, due to a change in the radial dependence of the total spin-orbit
potential. The gap shift and a good fit to the -dependence can be
recovered when the like-particle tensor interaction is opposite in sign to that
required for the matrix.Comment: 5 pages, 4 figures, accepted for publication as Rapid Communication
in Physical Review
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