$^{96}_{36}$Kr$_{60}$–Low-Z Boundary of the Island of Deformation at N =60

Abstract : Prompt γ-ray spectroscopy of the neutron-rich $^{96}$Kr, produced in transfer- and fusion-induced fission reactions, has been performed using the combination of the Advanced Gamma Tracking Array and the VAMOS++ spectrometer. A second excited state, assigned to $J^π$ = $4^+$, is observed for the first time, and a previously reported level energy of the first 2+ excited state is confirmed. The measured energy ratio R4/2 = E($4^+$)/E($2^+$) = 2.12(1) indicates that this nucleus does not show a well-developed collectivity contrary to that seen in heavier N = 60 isotones. This new measurement highlights an abrupt transition of the degree of collectivity as a function of the proton number at Z = 36, of similar amplitude to that observed at N = 60 at higher Z values. A possible reason for this abrupt transition could be related to the insufficient proton excitations in the g9/2, d5/2, and s1/2 orbitals to generate strong quadrupole correlations or to the coexistence of competing different shapes. An unexpected continuous decrease of R4/2 as a function of the neutron number up to N = 60 is also evidenced. This measurement establishes the Kr isotopic chain as the low-Z boundary of the island of deformation for N = 60 isotones. A comparison with available theoretical predictions using different beyond mean-field approaches shows that these models fail to reproduce the abrupt transitions at N = 60 and Z = 36.
Type de document :
Article dans une revue
Physical Review Letters, American Physical Society, 2017, 118, pp.165201. 〈10.1103/PhysRevLett.118.162501〉
Liste complète des métadonnées

Littérature citée [45 références]  Voir  Masquer  Télécharger

http://hal.in2p3.fr/in2p3-01518704
Contributeur : Michel Lion <>
Soumis le : vendredi 5 mai 2017 - 11:24:21
Dernière modification le : mardi 16 janvier 2018 - 16:00:34
Document(s) archivé(s) le : dimanche 6 août 2017 - 12:28:37

Fichier

PhysRevLett.118.162501.pdf
Fichiers produits par l'(les) auteur(s)

Identifiants

Collections

Citation

J. Dudouet, A. Lemasson, G. Duchêne, M. Rejmund, E. Clément, et al.. $^{96}_{36}$Kr$_{60}$–Low-Z Boundary of the Island of Deformation at N =60. Physical Review Letters, American Physical Society, 2017, 118, pp.165201. 〈10.1103/PhysRevLett.118.162501〉. 〈in2p3-01518704〉

Partager

Métriques

Consultations de la notice

278

Téléchargements de fichiers

75