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

$^{96} {36}$Kr$ {60}$–Low-Z Boundary of the Island of Deformation at N =60 - Descarga este documento en PDF. Documentación en PDF para descargar gratis. Disponible también para leer online.

1 IPNL - Institut de Physique Nucléaire de Lyon 2 GANIL - Grand Accélérateur National d-Ions Lourds 3 IPHC - Institut Pluridisciplinaire Hubert Curien 4 CSNSM - Centre de Sciences Nucléaires et de Sciences de la Matière 5 IPNO - Institut de Physique Nucléaire d-Orsay 6 LPSC - Laboratoire de Physique Subatomique et de Cosmologie 7 IRFU - Institut de Recherches sur les lois Fondamentales de l-Univers

Abstract : Prompt γ-ray spectroscopy of the neutron-rich $^{96}$Kr, produced in transfer- and fusion-induced fissionreactions, has been performed using the combination of the Advanced Gamma Tracking Array and theVAMOS++ spectrometer. A second excited state, assigned to $J^π$ = $4^+$, is observed for the first time, anda previously reported level energy of the first 2+ excited state is confirmed. The measured energy ratioR4-2 = E$4^+$-E$2^+$ = 2.121 indicates that this nucleus does not show a well-developed collectivitycontrary to that seen in heavier N = 60 isotones. This new measurement highlights an abrupt transition ofthe degree of collectivity as a function of the proton number at Z = 36, of similar amplitude to thatobserved at N = 60 at higher Z values. A possible reason for this abrupt transition could be related to theinsufficient proton excitations in the g9-2, d5-2, and s1-2 orbitals to generate strong quadrupole correlationsor 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.

Autor: J. Dudouet - A. Lemasson - G. Duchêne - M. Rejmund - E. Clément - C. Michelagnoli - F. Didierjean - A. Korichi - G. Maquart - O

Fuente: https://hal.archives-ouvertes.fr/


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