Shape Coexistence and Mixing in 152Sm

TL;DR

This paper investigates the low-energy structure of 152Sm through experimental methods, revealing strong mixing of coexisting bands and clarifying the absence of two-phonon beta-vibrational states.

Contribution

It provides detailed experimental data and two-band mixing calculations that describe the collective structure of 152Sm with high precision, highlighting the coexistence of near-degenerate bands.

Findings

No two-phonon beta-vibrational states found

Level energies and transition rates match calculations within ~10%

Strong mixing of coexisting quasi-rotational bands

Abstract

Experimental studies of 152Sm using multiple-step Coulomb excitation and inelastic neutron scattering provide key data that clarify the low-energy collective structure of this nucleus. No candidates for two-phonon beta-vibrational states are found. Experimental level energies of the ground-state and first excited (0+ state) rotational bands, electric monopole transition rates, reduced quadrupole transition rates, and the isomer shift of the first excited 2+ state are all described within ~10% precision using two-band mixing calculations. The basic collective structure of 152Sm is described using strong mixing of near-degenerate coexisting quasi-rotational bands with different deformations.