Physics Letters B (Sep 2016)

Quadrupole moments of odd-A 53−63Mn: Onset of collectivity towards N=40

  • C. Babcock,
  • H. Heylen,
  • M.L. Bissell,
  • K. Blaum,
  • P. Campbell,
  • B. Cheal,
  • D. Fedorov,
  • R.F. Garcia Ruiz,
  • W. Geithner,
  • W. Gins,
  • T. Day Goodacre,
  • L.K. Grob,
  • M. Kowalska,
  • S.M. Lenzi,
  • B. Maass,
  • S. Malbrunot-Ettenauer,
  • B. Marsh,
  • R. Neugart,
  • G. Neyens,
  • W. Nörtershäuser,
  • T. Otsuka,
  • R. Rossel,
  • S. Rothe,
  • R. Sánchez,
  • Y. Tsunoda,
  • C. Wraith,
  • L. Xie,
  • X.F. Yang

DOI
https://doi.org/10.1016/j.physletb.2016.07.016
Journal volume & issue
Vol. 760, no. C
pp. 387 – 392

Abstract

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The spectroscopic quadrupole moments of the odd–even Mn isotopes between N=28 and N=38 have been measured using bunched-beam collinear laser spectroscopy at ISOLDE, CERN. In order to increase sensitivity to the quadrupole interaction, the measurements have been done using a transition in the ion rather than in the atom, with the additional advantage of better spectroscopic efficiency. Since the chosen transition is from a metastable state, optical pumping in ISOLDE's cooler and buncher (ISCOOL) was used to populate this state. The extracted quadrupole moments are compared to large-scale shell model predictions using three effective interactions, GXPF1A, LNPS and modified A3DA. The inclusion of both the 1νg9/2 and 2νd5/2 orbitals in the model space is shown to be necessary to reproduce the observed increase in the quadrupole deformation from N=36 onwards. Specifically, the inclusion of the 2νd5/2 orbital induces an increase in neutron and proton excitations across the reduced gaps at N=40 and Z=28, leading to an increase in deformation above N=36.

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