Quadrupole collectivity in neutron-rich Cd isotopes

11th International Spring Seminar on Nuclear Physics: Shell Model and Nuclear Structure – achievements of the past two decades

Bönig, S.^1,3 ; Kröll, Th^1 ; Ilieva, S.^1 ; Scheck, M.^1,2,3

Institut für Kernphysik, Technische Universität Darmstadt, Darmstadt, Germany^1

School of Engineering, University of the West of Scotland, Paisley, United Kingdom^2

SUPA, Scottish Universities Physics Alliance, Glasgow, United Kingdom^3

关键词: Closed shells;    Coulomb excitation;    Mean-field calculations;    Nuclear theory;    Quadrupole moments;    Quadrupoles;    Shell models;    Transition strengths;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/580/1/012023/pdf
DOI  :  10.1088/1742-6596/580/1/012023

来源: IOP

【 摘 要 】

The proximity to the closed shells at Z 50 and N 82 makes the neutron-rich Cd isotopes a perfect test case for nuclear theories. The energy of the first excited 2+-state in the even122-128shows an irregular behaviour as the Cd isotopes exhibit only a slight increase for122Cd to126Cd and even a decrease from126Cd to128Cd. This anomaly can so far not be reproduced by shell model calculations. Only beyond mean field calculations with a resultant prolate deformation are capable to describe this anomalous behaviour. In order to gain more information about the neutron-rich Cd isotopes a Coulomb excitation experiment was performed with MINIBALL at REX-ISOLDE, CERN. The extracted transition strengths B (E2,0+gs 2+1) for122,124,126,128Cd agree with beyond mean field calculations. The spectroscopic quadrupole moments Qs (2+1) are compared with measurements on odd neutron-rich Cd isotopes.