Single-particle and collective excitations in the N=28 isotones Fe 54 and Mn 53

TY - JOUR

T1 - Single-particle and collective excitations in the N=28 isotones Fe 54 and Mn 53

AU - Rudolph, D.

AU - Ragnarsson, I.

AU - Andreoiu, C.

AU - Bentley, M. A.

AU - Carpenter, M. P.

AU - Charity, R. J.

AU - Clark, R. M.

AU - Ekman, J.

AU - Fahlander, C.

AU - Fallon, P.

AU - Reviol, W.

AU - Sarantites, D. G.

AU - Seweryniak, D.

N1 - Funding Information: We would like to thank the accelerator crews and the Gammasphere support staff at Argonne and Berkeley for their supreme efforts. This research used resources of ANL's ATLAS facility, which is a DOE Office of Science User Facility. This work is supported in part by the Swedish Research Council (Vetenskapsrådet, VR 2016-3969) and the U.S. Department of Energy under Grants No. DE-AC02-05CH11231 (LBNL), No. DE-AC02-06CH11357 (ANL), and No. DE-FG05-88ER-40406 (WU). Publisher Copyright: © 2020 authors. Published by the American Physical Society.

PY - 2020/7/21

Y1 - 2020/7/21

N2 - The fusion-evaporation reaction S32+Si28 at 125 MeV beam energy was used to populate high-spin states in the semimagic N=28 nuclei Mn53 and Fe54. With a combination of the Gammasphere spectrometer and ancillary devices including the Microball CsI(Tl) array, extensive high-spin level schemes are derived. They exhibit rotational-like collective structures and competing single-particle excitations. The experimental results are compared with predictions from shell-model calculations, for which the inclusion of isopin-symmetry-breaking terms is found to improve the description. An interpretation of the high-spin states is put forward using cranked Nilsson-Strutinsky calculations, indicative of contributions from collective excitations beyond some 8-MeV excitation energy and highlighting the importance of the g9/2 intruder orbital in this energy range.

AB - The fusion-evaporation reaction S32+Si28 at 125 MeV beam energy was used to populate high-spin states in the semimagic N=28 nuclei Mn53 and Fe54. With a combination of the Gammasphere spectrometer and ancillary devices including the Microball CsI(Tl) array, extensive high-spin level schemes are derived. They exhibit rotational-like collective structures and competing single-particle excitations. The experimental results are compared with predictions from shell-model calculations, for which the inclusion of isopin-symmetry-breaking terms is found to improve the description. An interpretation of the high-spin states is put forward using cranked Nilsson-Strutinsky calculations, indicative of contributions from collective excitations beyond some 8-MeV excitation energy and highlighting the importance of the g9/2 intruder orbital in this energy range.

UR - http://www.scopus.com/inward/record.url?scp=85089270939&partnerID=8YFLogxK

U2 - 10.1103/PhysRevC.102.014316

DO - 10.1103/PhysRevC.102.014316

M3 - Article

AN - SCOPUS:85089270939

SN - 2469-9985

VL - 102

JO - Physical Review C

JF - Physical Review C

IS - 1

M1 - 014316

ER -