Work

Towards large-scale shell-model studies of superheavy nuclei: Spectroscopy of N ∼ 150 nuclei

Year: 2026

Type: article

Abstract: Transfermium nuclei provide experimental access to the single-particle structure underlying the stability of superheavy nuclei. We present the first systematic shell-model description of the N = 150 isotones using a new variation-after-projection shell-model approach. The ground-state and K π = 2 − bands are reproduced across the isotonic chain with a unified Hamiltonian, including the long-standing anomalous lowering of the J π = 2 − bandhead in 248 Cf. We show that this anomaly originates from a local inversion of the neutron j 15/2 and g 9/2 orbitals, associated with the deformed [734]9/2 and [622]5/2 neutron orbitals near the Fermi surface. This is driven by the proton-neutron monopole interaction as proton occupations evolve along the isotonic chain. The same mechanism also reproduces the low-lying spectra of the neighboring N = 151 isotones, without further adjustment, and predicts a low-lying J π = 2 − bandhead at 524 keV in 254 Rf. This work establishes a microscopic shell-model benchmark for the key neutron single-particle levels in the heavy actinide and transfermium region and demonstrates the feasibility of large-scale shell-model calculations for superheavy nuclei.

Source: Physics Letters B

DOI: 10.1016/j.physletb.2026.141069

Authors: Zhanjiang Lian, Zaochun Gao, Chong Qi

Institutions: China Institute of Atomic Energy, KTH Royal Institute of Technology

Language: English

Topic: Nuclear physics research studies

Subfield: Nuclear and High Energy Physics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: diamond

Funders: China Institute of Atomic Energy, National Key Research and Development Program of China Stem Cell and Translational Research

Award: G8351945893