Deformed band structures in neutron-rich ${}^{152-158}$Pm isotopes

Abstract

High spin band structures of neutron-rich ${}^{152-158}$Pm isotopes have been obtained from the measurement of prompt $\gamma$-rays of isotopically identified fragments produced in fission of ${}^{238}$U+${}^9$Be and detected using the VAMOS++ magnetic spectrometer and EXOGAM segmented Clover array at GANIL and also from the high statistics $\gamma$-$\gamma$-$\gamma$ and $\gamma$-$\gamma$-$\gamma$-$\gamma$ data from the spontaneous fission of ${}^{252}$Cf using Gammasphere. The excited states in ${}^{157}$Pm and those above the isomers in even-A Pm isotopes ${}^{152,154,156,158}$Pm have been identified for the first time. The spectroscopic information on the rotational band structures in odd-A Pm isotopes has been extended considerably to higher spins and the possibility of the presence of reflection asymmetric shapes is explored. The configuration assignments are based on the results of Cranked Relativistic Hartree-Bogoliubov calculations. From the systematics of bands in odd-A Pm isotopes and weak population of opposite parity bands, octupole deformed shapes in neutron rich Pm isotopes beyond $N=90$ seem unlikely to be present.

References in corpus (5)

• The effective force NL3 revisited
• Direct Evidence of Octupole Deformation in Neutron-Rich ${}^{144}$Ba
• Octupole deformation in the ground states of even-even nuclei: a global analysis within the covariant density functional theory
• Cranked Relativistic Hartree-Bogoliubov Theory: Formalism and Application to the Superdeformed Bands in the $A\sim 190$ region
• Identification of new transitions and mass assignments of levels in ${}^{143-153}$Pr

Cited by in corpus (3)

• Fast trajectory reconstruction techniques for the large acceptance magnetic spectrometer VAMOS++
• Configuration and bandhead spin assignments for the 2-quasiparticle rotational bands in the neutron-rich nuclei ${}^{154,156}$Pm
• Level structure of light neutron-rich La isotopes beyond the N=82 shell closure