Fricz, DorianMenéndez Sánchez, JavierRíos Huguet, ArnauBally, BenjaminRodríguez, Tomás R.Márquez Romero, Antonio2025-01-242025-01-242024-11-252469-9985https://hdl.handle.net/2445/217962We 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.1 p.application/pdfeng(c) American Physical Society, 2024ElectromagnetismeFísica nuclearEstructura nuclearElectromagnetismNuclear physicsNuclear structureinfo:eu-repo/semantics/article7533322025-01-24info:eu-repo/semantics/openAccess