Continuing influence of shell effects at high-excitation energies

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Date

2019

Journal Title

Journal ISSN

Volume Title

Publisher

Elsevier

Abstract

Empirical drops in ground-state nuclear polarizabilities indicate deviations from the effect of giant dipole resonances and may reveal the presence of shell effects in semi-magic nuclei with neutron magic numbers N = 50, 82 and 126. Similar drops of polarizability in the quasi-continuum of nuclei with, or close to, magic numbers N = 28, 50 and 82, could reflect the continuing influence of shell closures up to the nucleon separation energy. These findings open a new avenue to investigating magic numbers at high-excitation energies and strongly support recent large-scale shell-model calculations in the quasi- continuum region, which describe the origin of the low-energy enhancement of the photon strength function as induced paramagnetism. The nuclear-structure dependence of the photon-strength function asserts the generalized Brink-Axel hypothesis as more universal than originally expected.

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Keywords

Energy, Astronomy, Physics, Cosmology, Nuclear

Citation

Ngwetsheni, C., & Orce, J. N. (2019). Continuing influence of shell effects at high-excitation energies. Physics Letters B, 792 , 335-339. https://doi.org/10.1016/j.physletb.2019.03.021