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

Autor: Rudolph, D, Ragnarsson, I, Andreoiu, C, Bentley, MA, Carpenter, MP, Charity, RJ, Clark, RM, Ekman, J, Fahlander, C, Fallon, P, Reviol, W, Sarantites, DG, Seweryniak, D
Rok vydání: 2020
Předmět:
Zdroj: Physical Review C, vol 102, iss 1
Popis: 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.
Databáze: OpenAIRE