Self-consistent description of dysprosium isotopes in the doubly midshell region

Abstract

Ground-state deformations, binding energies, and potential energy surfaces have been calculated for eveneven dysprosium isotopes between 160 Dy and 180 Dy in the framework of density-dependent Hartree-Fock calculations with BCS pairing correlations. Further deformed Hartree-Fock with angular-momentum projection and band-mixing calculations explore the yrast spectra of the nuclides approaching the neutron midshell. Predictions of high-K states in the doubly midshell nucleus 66 170 Dy 104 are made.

Systematic study of high-K isomers in the midshell Gd and Dy nuclei

“…This is also supported by Skyrme Hartee-Fock and Projected Hartree-Fock calculations in Ref. [10]. In both the articles, a high-K isomer at low excitation energy is predicted [9,10].…”

“…[10]. In both the articles, a high-K isomer at low excitation energy is predicted [9,10]. However, a recent measurement [11] shows that the K π = 6 + isomer decay hindrance factor is reduced by an order of magnitude compared to the predictions.…”

Isomer Decay Spectroscopy ofSm164andGd166Patel1, Söderström2, Podolyák3 et al. 2014Phys. Rev. Lett.559380View full textAdd to dashboardCite

“…Hartree-Fock calculations using a variety of Skyrme parametrizations were performed on Dy isotopes in Ref. [27]. The majority of Skyrme forces predict a maximum deformation at N ¼ 102, while others place it at N ¼ 100.…”

Collective And Single-particle Structures In The Neutron-rich Doubly Mid-shell Nucleus 170Dy

“…Neglecting any potential sub-shell closures, the nucleus with A < 208 that has the largest number of valence particles is 170 66 Dy 104 , lying precisely in the middle of the closed proton Z = 50, 82 and neutron N = 82, 126 shells, with Z = 66 and N = 104. Thus, 170 Dy has become a central calibration point for tests of collective as well as single-particle models [1,2,3,4]. The amount of collectivity has been shown to have a smooth dependence on both the energy of the first excited state, E(2 + ), and the reduced transition probability from the first state to the ground state, B(E2:2 + → 0 + ), as well as the energy ratio of the first excited 4 + and 2 + states, E(4 + )/E(2 + ).…”

“…What speaks against this simplistic picture are possible deformed and spherical sub-shell closures and other deviations from the smooth systematics that are observed in, for example, 190 W [5,6,7] and along the N = 100 isotone chain [8,9,10], the latter illustrated in Figure 1. Indeed, some theoretical studies predict that the quadrupole deformation maximum occurs below the N = 104 mid-shell neutron number within an isotope chain [4,3,11], while experimental data indicate that the deformation increases as Z decreases below mid-shell [9,10]. From a single-particle point of view, one predicted property of 170 Dy is the long-lived K π = 6 + two quasi-particle isomer [3,4,12], where K is the total angular momentum projection on the prolate symmetry axis.…”