R. Rodr\'ıguez-Guzmán

arXiv2026

Prospects for modelling odd and odd-odd nuclei using energy density functionals

About half of particle-bound nuclei have an odd number of nucleons. About one quarter more are odd-odd, meaning they have an odd number of neutrons and an odd number of protons. In this context, it is about time to shift the 70-odd-year focus of theories using nuclear energy density functionals (EDFs) away from the remaining one-quarter of even-even nuclei. This White Paper aims to present open, unresolved problems and promising research directions in nuclear EDFs that were discussed during the 2024 ESNT workshop in Saclay, France, on ``The microscopic modelling of odd-mass and odd-odd nuclei''.

nucl-th↗

arXiv2026

Impacts of hexadecapole correlations in actinide nuclei

The impact of hexadecapole correlations on the low-energy spectroscopic properties of Th, U, and Pu nuclei, within the mass range $232 \le A \le 240$, is studied systematically using the mapped $sdg$-IBM model. Fermionic input is obtained via the quadrupole-hexadecapole constrained Hartree-Fock-Bogoliubov approximation, based on the parametrization D1S of the Gogny energy density functional. The $sdg$-IBM Hamiltonian parameters are determined by mapping the quadrupole-hexadecapole fermionic mean-field potential energy surfaces onto the corresponding bosonic surfaces. The low-energy spectra and transition strengths, obtained via the diagonalization of the $sdg$-IBM Hamiltonian, compare well with the available experimental data. It is shown that the effects of hexadecapole collectivity can be observed in high-spin yrast states with spins $J^π \geqslant 10^{+}$. The mapped $sdg$-IBM improves the excitation energies of those states, as compared with the simpler $sd$-IBM model. The $sdg$-IBM also improves the description of the $E2$ transition strengths between high-spin yrast states and predicts strong $E4$ transitions from nonyrast $4^+$ states to the $0^+$ ground state.

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