Probing the N=14 subshell closure: g factor of the Mg26(21+) state

B.P. McCormick; A.E. Stuchbery; T. Kibédi; G.J. Lane; M.W. Reed; T.K. Eriksen; S.S. Hota; B.Q. Lee; N. Palalani

Physics Letters B (Apr 2018)

Probing the N=14 subshell closure: g factor of the Mg26(21+) state

B.P. McCormick,
A.E. Stuchbery,
T. Kibédi,
G.J. Lane,
M.W. Reed,
T.K. Eriksen,
S.S. Hota,
B.Q. Lee,
N. Palalani

Affiliations

B.P. McCormick: Department of Nuclear Physics, RSPE, Australian National University, Canberra, ACT 2601, Australia
A.E. Stuchbery: Corresponding author.; Department of Nuclear Physics, RSPE, Australian National University, Canberra, ACT 2601, Australia
T. Kibédi: Department of Nuclear Physics, RSPE, Australian National University, Canberra, ACT 2601, Australia
G.J. Lane: Department of Nuclear Physics, RSPE, Australian National University, Canberra, ACT 2601, Australia
M.W. Reed: Department of Nuclear Physics, RSPE, Australian National University, Canberra, ACT 2601, Australia
T.K. Eriksen: Department of Nuclear Physics, RSPE, Australian National University, Canberra, ACT 2601, Australia
S.S. Hota: Department of Nuclear Physics, RSPE, Australian National University, Canberra, ACT 2601, Australia
B.Q. Lee: Department of Nuclear Physics, RSPE, Australian National University, Canberra, ACT 2601, Australia
N. Palalani: Department of Nuclear Physics, RSPE, Australian National University, Canberra, ACT 2601, Australia

Journal volume & issue: Vol. 779
pp. 445 – 451

Abstract

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The first-excited state g factor of 26Mg has been measured relative to the g factor of the Mg24(21+) state using the high-velocity transient-field technique, giving g=+0.86±0.10. This new measurement is in strong disagreement with the currently adopted value, but in agreement with the sd-shell model using the USDB interaction. The newly measured g factor, along with E(21+) and B(E2) systematics, signal the closure of the νd5/2 subshell at N=14. The possibility that precise g-factor measurements may indicate the onset of neutron pf admixtures in first-excited state even–even magnesium isotopes below 32Mg is discussed and the importance of precise excited-state g-factor measurements on sd shell nuclei with N≠Z to test shell-model wavefunctions is noted. Keywords: g factors, Transient-field, 26Mg, Shell-model calculations, sd shell, Island of inversion

Published in Physics Letters B

ISSN: 0370-2693 (Print); 1873-2445 (Online)
Publisher: Elsevier
Country of publisher: Netherlands
LCC subjects: Science: Physics
Website: http://www.journals.elsevier.com/physics-letters-b/

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