Electromagnetic transition strengths in soft deformed nuclei

Abstract

Spectroscopic observables such as electromagnetic transitions strengths can be related to the properties of the intrinsic mean-field wave function when the latter are strongly deformed, but the standard rotational formulas break down when the deformation decreases. Nevertheless there is a well-defined, non-zero, spherical limit that can be evaluated in terms of overlaps of mean-field intrinsic deformed wave functions. We examine the transition between the spherical limit and strongly deformed one for a range of nuclei comparing the two limiting formulas with exact projection results. We find a simple criterion for the validity of the rotational formula depending on $<\Delta {\vec{J}}^2>$, the mean square fluctuation in the angular momentum of the intrinsic state. We also propose an interpolation formula which describes the transition strengths over the entire range of deformations, reducing to the two simple expressions in the appropriate limits.

16 pages, 5 figures, supplemental material included

References in corpus (4)

• Structure of even-even nuclei using a mapped collective Hamiltonian and the D1S Gogny interaction
• Global systematics of octupole excitations in even-even nuclei
• Beyond the relativistic mean-field approximation (III): collective Hamiltonian in five dimensions
• Quadrupole collective states within the Bohr collective Hamiltonian

Cited by in corpus (12)

• Mean field and beyond description of nuclear structure with the Gogny force: A review
• Direct Evidence of Octupole Deformation in Neutron-Rich ${}^{144}$Ba
• Symmetry restoration in mean-field approaches
• Correlating Schiff moments in the light actinides with octupole moments
• The observation of vibrating pear shapes in radon nuclei: update
• Microscopic description of quadrupole-octupole coupling in actinides with the Gogny-D1M energy density functional
• Enhancement of octupole strength in near spherical nuclei
• Simultaneous analysis of matter radii, transition probabilities, and excitation energies of Mg isotopes by angular-momentum-projected configuration-mixing calculations
• Investigation of octupole collectivity near the $A=72$ shape-transitional point
• Nuclear structure investigation of even-even and odd Pb isotopes by using the Hartree-Fock-Bogoliubov method
• Near-threshold correlations of neutrons
• Separation Between d${}_{5/2}$ and s${}_{1/2}$ Neutron Single Particle Strength in ${}^{15}$N