6 research outputs found
Role of dynamical particle-vibration coupling in reconciliation of the puzzle for spherical proton emitters
It has been observed that decay rate for proton emission from
single particle state is systematically quenched compared with the prediction
of a one dimensional potential model although the same model successfully
accounts for measured decay rates from and states. We
reconcile this discrepancy by solving coupled-channels equations, taking into
account couplings between the proton motion and vibrational excitations of a
daughter nucleus. We apply the formalism to proton emitting nuclei
Re to show that there is a certain range of parameter set of the
excitation energy and the dynamical deformation parameter for the quadrupole
phonon excitation which reproduces simultaneously the experimental decay rates
from the 2, 3 and 1 states in these nuclei.Comment: RevTex, 12 pages, 4 eps figure
Microscopic Structure of High-Spin Vibrational Excitations in Superdeformed 190,192,194Hg
Microscopic RPA calculations based on the cranked shell model are performed
to investigate the quadrupole and octupole correlations for excited
superdeformed bands in 190Hg, 192Hg, and 194Hg. The K=2 octupole vibrations are
predicted to be the lowest excitation modes at zero rotational frequency. At
finite frequency, however, the interplay between rotation and vibrations
produces different effects depending on neutron number: The lowest octupole
phonon is rotationally aligned in 190Hg, is crossed by the aligned
two-quasiparticle bands in 192Hg, and retains the K=2 octupole vibrational
character up to the highest frequency in 194Hg. The gamma vibrations are
predicted to be higher in energy and less collective than the octupole
vibrations. From a comparison with the experimental dynamic moments of inertia,
a new interpretation of the observed excited bands invoking the K=2 octupole
vibrations is proposed, which suggests those octupole vibrations may be
prevalent in SD Hg nuclei.Comment: 22 pages, REVTeX, 12 postscript figures are available on reques
Identification of 181Hg and shape coexistence in odd-A Hg isotopes
In-beam γ-ray transitions in 181Hg, the lightest odd-A Hg isotope known thus far, have been identified from fragment mass-γ and γ-γ coincidence measurements. Five prolate deformed rotational bands were placed in the level scheme. A decoupled band built on the strongly prolate deformed 1/2-[521] ground state was observed up to 29/2-. A 5/2-[512] configuration is suggested for a pair of strongly coupled bands displaying no signature splitting. The other two bands are also signature partner bands. They are populated with the largest intensity and exhibit splitting. They have been associated with the mixed neutron i13/2 orbitals and are proposed to decay to an i13/2 isomeric state associated with an oblate state