0000000001130138
AUTHOR
T. Otsuka
Enhanced Quadrupole and Octupole Strength in Doubly Magic ^{132}Sn.
International audience; The first $2^+$ and $3^-$ states of the doubly magic nucleus $^{132}$Sn are populated via safe Coulomb excitation employing the recently commissioned HIE-ISOLDE accelerator at CERN in conjunction with the highly efficient MINIBALL array. The $^{132}$Sn ions are accelerated to an energy of 5.49 MeV/nucleon and impinged on a $^{206}$Pb target. Deexciting $\gamma$ rays from the low-lying excited states of the target and the projectile are recorded in coincidence with scattered particles. The reduced transition strengths are determined for the transitions $0_{g.s.}^+ \rightarrow 2_1^+$, $0_{g.s.}^+ \rightarrow 3_1^-$, and $2_1^+ \rightarrow 3_1^-$ in $^{132}$Sn. The res…
Microscopic structure of coexisting $0^+$ states in $^{68}$Ni probed via two-neutron transfer
© 2019 authors. Published by the American Physical Society. Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI. The structure of low-spin states originating from shape-coexisting configurations in Ni284068 was directly probed via the two-neutron transfer reaction Ni66(t,p)Ni68 in inverse kinematics using a radioactive ion beam on a radioactive target. The direct feeding to the first excited 0+ state was measured for center-of-mass angles 4-16 and amounts to an integral of 4.2(16)% rela…
Dipole and quadrupole moments of $^{73-78}$Cu as a test of the robustness of the $Z=28$ shell closure near $^{78}$Ni
Nuclear spins and precise values of the magnetic dipole and electric quadrupole moments of the ground states of neutron-rich Cu73–78 isotopes were measured using the Collinear Resonance Ionization Spectroscopy (CRIS) experiment at the CERN On-Line Isotope Mass Separator (ISOLDE) facility. The nuclear moments of the less exotic Cu73,75 isotopes were remeasured with similar precision, yielding values that are consistent with earlier measurements. The moments of the odd-odd isotopes, and 2978Cu (N=49) in particular, are used to investigate excitations of the assumed doubly magic Ni78 core through comparisons with large-scale shell-model calculations. Despite the narrowing of the Z=28 shell gap…
Spins and Magnetic Moments of $^{49}$K and $^{51}$K: establishing the 1/2$^+$ and 3/2$^+$ level ordering beyond $N$ = 28
The ground-state spins and magnetic moments of $^{49,51}$K have been measured using bunched-beam high-resolution collinear laser spectroscopy at ISOLDE-CERN. For $^{49}$K a ground-state spin $I = 1/2$ was firmly established. The observed hyperfine structure of $^{51}$K requires a spin $I > 1/2$ and from its magnetic moment $\mu(^{51}\text{K})= +0.5129(22)\, \mu_N$ a spin/parity $I^\pi=3/2^+$ with a dominant $\pi 1d_{3/2}^{-1}$ hole configuration was deduced. This establishes for the first time the re-inversion of the single-particle levels and illustrates the prominent role of the residual monopole interaction for single-particle levels and shell evolution.
Investigating the large deformation of the 5/2(+) isomeric state in Zn-73: An indicator for triaxiality
Recently reported nuclear spins and moments of neutron-rich Zn isotopes measured at ISOLDE-CERN [C. Wraith et al., Phys. Lett. B 771, 385 (2017)PYLBAJ0370-269310.1016/j.physletb.2017.05.085] show an uncommon behavior of the isomeric state in Zn73. Additional details relating to the measurement and analysis of the Zn73m hyperfine structure are addressed here to further support its spin-parity assignment 5/2+ and to estimate its half-life. A systematic investigation of this 5/2+ isomer indicates that significant collectivity appears due to proton/neutron E2 excitations across the proton Z = 28 and neutron N = 50 shell gaps. This is confirmed by the good agreement of the observed quadrupole mo…