Электронный каталог

Статья

Seif, W.
Stability of Transuranic and Transfermium Isomers : Single-Particle Structure Implications and *a Decays / W.Seif, A.R.Abdulghany. – Text : electronic // The European Physical Journal A. – 2025. – Vol. 61, No. 11. – P. 269. – URL: https://doi.org/10.1140/epja/s10050-025-01726-y. – Bibliogr.: 96.

The transuranic-transfermium region (Z ≥ 92) hosts 221 known isomers across 160 isotopes. We examine their single-particle configurations and α-decay stability relative to ground states. Our analysis reveals that proton or neutron shell/subshell closures enhance isomer production and stabilize high-spin multi-quasiparticle configurations by strengthening couplings between complementary valence nucleons. Evidenced deformed sub-shell closure at Z = 96 [Z = 104] boosts isomer yields attributed to occupations in π5/2+[642](1i13/2+), π5/2−[523](1h9/2−) and π7/2+[633](1i13/2+) [π9/2+[624](1i13/2+), π1/2−[521] (2 f5/2−) and π7/2−[514](1h9/2−)] orbitals. A neutron deformed shell gap at N = 152 promotes isomerism in N = 151, 153 isotones, primarily through ν5/2+[622](1i11/2+), ν11/2−[725](1 j15/2−), and ν9/2−[734](1 j15/2−) excitations. The leading quasi-particle configurations in the isomers of N = 147–149 isotones originate from neutrons/ holes in the ν7/2+[624](2g9/2+) and ν1/2+[631] (3d5/2+) orbitals. The most stable isomers are predominantly driven by excitations in the π1i13/2+ and ν1 j15/2− orbitals, under moderate prolate deformation, with key contributions from theπ11/2+[615],π9/2+[624],π7/2+[633], π5/2+[642], ν11/2−[725], ν9/2−[734], and ν7/2−[743] states, then from deformed states of the π2 f7/2− and ν1i11/2+ orbitals. Unlike heavier transfermiums, isomers (iso) of the Np–Es isotopes (N = 127–144 isotones) exhibit no α- decays. The limited data constrain log10 T (iso) α to a single linear trend versus _ Q−1 α for favored and unfavored decays, unlike the ground-state decays where the trend’s slope correlates with the transferred angular momentum (_l), with stability enhanced against high-_l decays. The α-preformation factor in isomers S(iso) α exceeds ground-state (gs) value only when Q(iso) α ≤ Q(gs) α and _l is low; otherwise, S(iso) α drops by 1–3 orders of magnitude, decreasing with both Q(iso) α and _l. This study reveals transactinide isomers as a promising research direction for finding stable configurations in undiscovered superheavy nuclei.



ОИЯИ = ОИЯИ (JINR)2025
Спец.(статьи,препринты) = С 341.2в1 - Изомеры и метастабильные состояния. Высокоспиновые состояния
Спец.(статьи,препринты) = С 341.1д - Альфа-распад, протонный распад и другие виды распада