Shell-model study of 28 Si: Coexistence of oblate, prolate, and superdeformed shapes

We study the shape coexistence in the nucleus 28 Si with the nuclear shell model using numerical diagonalizations complemented with variational calculations based on the projected generator-coordinate method. The theoretical electric quadrupole moments and transitions as well as the collective wave...

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Detalles Bibliográficos
Autores: Fricz, Dorian, Menéndez Sánchez, Javier, Rios Huguet, Arnau, Bally, Benjamin, Rodríguez, Tomás R., Márquez Romero, Antonio
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2024
País:España
Institución:Universidad de Barcelona
Repositorio:Dipòsit Digital de la UB
OAI Identifier:oai:diposit.ub.edu:2445/217962
Acceso en línea:https://hdl.handle.net/2445/217962
Access Level:acceso abierto
Palabra clave:Electromagnetisme
Física nuclear
Estructura nuclear
Electromagnetism
Nuclear physics
Nuclear structure
Descripción
Sumario:We study the shape coexistence in the nucleus 28 Si with the nuclear shell model using numerical diagonalizations complemented with variational calculations based on the projected generator-coordinate method. The theoretical electric quadrupole moments and transitions as well as the collective wave functions indicate that the standard USDB interaction in the sd shell describes well the ground-state oblate rotational band, but misses theexperimental prolate band. Guided by the quasi-SU(3) model, we show that the prolate band can be reproduced in the sd shell by reducing the energy of the 0d 3/2 orbital. Alternatively, in the extended sd p f configuration space a modification of the SDPF-NR interaction that accommodates cross-shell excitations also reproduces the oblate and prolate bands. Finally, we address the possibility of superdeformation in 28 Si within the sd p f space. Our results indicate that superdeformed structures appear at about 18–20 MeV.