328 research outputs found
Deformation effects in Giant Monopole Resonance
The isoscalar giant monopole resonance (GMR) in Samarium isotopes (from
spherical Sm to deformed Sm) is investigated within the
Skyrme random-phase-approximation (RPA) for a variety of Skyrme forces. The
exact RPA and its separable version (SRPA) are used for spherical and deformed
nuclei, respectively. The quadrupole deformation is shown to yield two effects:
the GMR broadens and attains a two-peak structure due to the coupling with the
quadrupole giant resonance.Comment: 6 pages, 4 figures, proceedings of 11th Intern. Spring Seminar on
Nuclear Physics (Ischia, Italy, May 12-16, 2014
Toroidal, compression, and vortical dipole strengths in Sm: Skyrme-RPA exploration of deformation effect
A comparative analysis of toroidal, compressional and vortical dipole
strengths in the spherical Sm and the deformed Sm is performed
within the random-phase-approximation using a set of different Skyrme forces.
Isoscalar (T=0), isovector (T=1), and electromagnetic excitation channels are
considered. The role of the nuclear convection and
magnetization currents is inspected. It is shown that the
deformation leads to an appreciable redistribution of the strengths and causes
a spectacular deformation splitting (exceeding 5 MeV) of the isoscalar
compressional mode. In Sm, the =0 and =1 branches of the mode
form well separated resonances. When stepping from Sm to Sm, we
observe an increase of the toroidal, compression and vortical contributions in
the low-energy region (often called pygmy resonance). The strength in this
region seems to be an overlap of various excitation modes. The energy centroids
of the strengths depend significantly on the isoscalar effective mass .
Skyrme forces with a large (typically ) seem to be
more suitable for description of experimental data for the isoscalar giant
dipole resonance.Comment: 13 pages, 10 figures, submitted to EJP
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