Revealing microscopic origins of shape coexistence in the Ni isotopic chain

• Published in: EPJ Web of conferences Vol. 223; p. 1032
• Main Authors: Leoni, Silvia, Fornal, Bogdan, Marginean, Nicolae, Sferrazza, Michele, Tsunod, Yusuke, Otsuka, Takaharu
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Les Ulis EDP Sciences 2019
• Subjects: Computer simulation; Isomers; Isotopes; Reaction mechanisms; Wave functions
• ISSN: 2100-014X; 2101-6275; 2100-014X
• DOI: 10.1051/epjconf/201922301032

In a two–neutron transfer experiment, performed in Bucharest in July 2016 at sub–Coulomb barrier energy,a photon decay hindered – solely – by a nuclear shape change was identified in the
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Ni nucleus. Such a rare process, at spin zero, was clearly observed before only in actinide nuclei in the 1970’s,where fission isomers were found. The experimental findings on
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Ni have been well reproduced by the Monte Carlo Shell Model Calculations of the Tokyo group, which predict a multifaceted scenario of coexistence of spherical, oblate and prolate shapes in neutron–rich Ni isotopes. The results on
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Ni encouraged a comprehensive gamma–spectroscopy investigation of neutron–rich Ni isotopes, in particular
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Ni and
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–Ni, at IFIN–HH (Bucharest), IPN Orsay and ILL (Grenoble), employing different reaction mechanisms to pin down the wave function composition of selected excited states. The aim is to shed light on the microscopic origin of deformation in neutron–rich Ni nuclei, possibly locating other examples of “shape–isomer–like” structures inthis region.