CERN Accelerating science

Published Articles
Title	$_{36}^{96}$Kr$_{60}$–low-$Z$ boundary of the island of deformation at $N=60$
Related title	Kr369660 –Low- Z Boundary of the Island of Deformation at N=60
Author(s)	Dudouet, J (Lyon, IPN) ; Lemasson, A (GANIL) ; Duchêne, G (Strasbourg, IPHC) ; Rejmund, M (GANIL) ; Clément, E (GANIL) ; Michelagnoli, C (GANIL) ; Didierjean, F (Strasbourg, IPHC) ; Korichi, A (CSNSM, Orsay ; GANIL) ; Maquart, G (Lyon, IPN) ; Stezowski, O (Lyon, IPN) ; Lizarazo, C (Darmstadt, Tech. Hochsch. ; Darmstadt, GSI) ; Pérez-Vidal, R M (Valencia U., IFIC) ; Andreoiu, C (Simon Fraser U., Dept. Chem.) ; de Angelis, G (INFN, Legnaro) ; Astier, A (CSNSM, Orsay) ; Delafosse, C (Orsay, IPN) ; Deloncle, I (CSNSM, Orsay) ; Dombradi, Z (Debrecen, Inst. Nucl. Res.) ; de France, G (GANIL) ; Gadea, A (Valencia U., IFIC) ; Gottardo, A (Orsay, IPN) ; Jacquot, B (GANIL) ; Jones, P (iThemba LABS) ; Konstantinopoulos, T (CSNSM, Orsay) ; Kuti, I (Debrecen, Inst. Nucl. Res.) ; Le Blanc, F (Strasbourg, IPHC) ; Lenzi, S M (INFN, Padua ; Padua U.) ; Li, G (Darmstadt, GSI) ; Lozeva, R (Strasbourg, IPHC ; CSNSM, Orsay) ; Million, B (INFN, Milan) ; Napoli, D R (INFN, Legnaro) ; Navin, A (GANIL) ; Petrache, C M (CSNSM, Orsay) ; Pietralla, N (Darmstadt, Tech. Hochsch.) ; Ralet, D (Darmstadt, Tech. Hochsch. ; CSNSM, Orsay) ; Ramdhane, M (LPSC, Grenoble) ; Redon, N (Lyon, IPN) ; Schmitt, C (GANIL) ; Sohler, D (Debrecen, Inst. Nucl. Res.) ; Verney, D (Orsay, IPN) ; Barrientos, D (CERN) ; Birkenbach, B (Cologne U.) ; Burrows, I (Daresbury) ; Charles, L (Strasbourg, IPHC) ; Collado, J (Valencia U., Dept. Ing. Electronica) ; Cullen, D M (Manchester U.) ; Désesquelles, P (CSNSM, Orsay) ; Pardo, C Domingo (Valencia U., IFIC) ; González, V (Valencia U., Dept. Ing. Electronica) ; Harkness-Brennan, L (Liverpool U.) ; Hess, H (Cologne U.) ; Judson, D S (Liverpool U.) ; Karolak, M (IRFU, Saclay) ; Korten, W (IRFU, Saclay) ; Labiche, M (Daresbury) ; Ljungvall, J (CSNSM, Orsay) ; Menegazzo, R (INFN, Padua) ; Mengoni, D (INFN, Padua ; Padua U.) ; Pullia, A (INFN, Milan ; Milan U.) ; Recchia, F (INFN, Padua ; Padua U.) ; Reiter, P (Cologne U.) ; Salsac, M D (IRFU, Saclay) ; Sanchis, E (Valencia U., Dept. Ing. Electronica) ; Theisen, Ch (IRFU, Saclay) ; Valiente-Dobón, J J (INFN, Legnaro) ; Zielińska, M (IRFU, Saclay)
Publication	2017
Number of pages	6
In:	Phys. Rev. Lett. 118 (2017) 162501
DOI	10.1103/PhysRevLett.118.162501
Subject category	Nuclear Physics - Experiment
Abstract	Prompt γ-ray spectroscopy of the neutron-rich 96Kr, produced in transfer- and fusion-induced fission reactions, has been performed using the combination of the Advanced Gamma Tracking Array and the VAMOSþþspectrometer. A second excited state, assigned to Jπ ¼ 4þ, is observed for the first time, and a previously reported level energy of the first 2þ excited state is confirmed. The measured energy ratio R4=2 ¼ Eð4þÞ=Eð2þÞ ¼ 2.12ð1Þ indicates that this nucleus does not show a well-developed collectivity contrary to that seen in heavier N ¼ 60 isotones. This new measurement highlights an abrupt transition of the degree of collectivity as a function of the proton number at Z ¼ 36, of similar amplitude to that observed at N ¼ 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 ¼ 60 is also evidenced. This measurement establishes the Kr isotopic chain as the low-Z boundary of the island of deformation for N ¼ 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 ¼ 60 and Z ¼ 36.
Copyright/License	publication: © 2017-2024 authors (License: CC-BY-4.0)

Corresponding record in: Inspire