2 research outputs found
Systematic investigation of quadrupole properties in deformed and transitional nuclei
In the present work, we address a long-standing problem in nuclear physics on
how to decipher the nature of collective motion from electromagnetic transition
probabilities. A systematic analysis of the transitions is performed
for thirty nuclei using the triaxial projected shell model (TPSM) approach. It
is shown that transitions for the -bands depict a
staggering phase and this phase reverses with the inclusion of the
quasiparticle excitations for all the nuclei, except for the six nuclei of
Ge, Ru, Er, Os, Pt and Th. This
feature is analogous to the energy staggering phase obtained for these nuclei.
It is noted that the energy staggering phase with even-spin-down
(odd-spin-down), which is considered as a signature of -softness
(-rigidity), corresponds to even-spin-up (odd-spin-up) staggering phase
of the transitions. Further, TPSM predicted values for both energies
and transition are shown to be in good agreement with the corresponding
experimental values.Comment: 24 pages, 28 figure
Triaxial projected shell model approach for negative parity states in even-even nuclei
The triaxial projected shell model (TPSM) approach is generalized to
investigate the negative parity band structures in even-even systems. In the
earlier version of the TPSM approach, the quasiparticle excitations were
restricted to one major oscillator shell and it was possible to study only
positive parity states in even-even systems. In the present extension, the
excited quasiparticles are allowed to occupy two major oscillator shells, which
makes it possible to generate the negative parity states. As a major
application of this development, the extended approach is applied to elucidate
the negative parity high-spin band structures in Ru and it is shown
that energies obtained with neutron excitation are slightly lower than the
energies calculated with proton excitation. However, the calculated aligned
angular momentum () clearly separates the two spectra with neutron
in reasonable agreement with the empirically evaluated from the
experimental data, whereas proton shows large deviations. Furthermore, we
have also deduced the transition quadrupole moments from the TPSM wavefunctions
along the negative-parity yrast- and yrare- bands and it is shown that these
quantities exhibit rapid changes in the bandcrossing region.Comment: 14 pages, 17 figure