Symmetry and shape coexistence in 10Be

TL;DR

This study uses ab initio calculations to analyze the nuclear shapes and rotational bands in 10Be, revealing coexistence of triaxial and prolate deformations supported by SU(3) symmetry analysis.

Contribution

It demonstrates how ab initio NCCI calculations combined with SU(3) symmetry elucidate shape coexistence and rotational behavior in 10Be.

Findings

Ground-state band is a triaxial rotor from SU(3) in 0 hbar omega space.

Excited K=0 band is a prolate rotor from SU(3) in 2 hbar omega space.

Results support shape coexistence in 10Be with distinct rotational modes.

Abstract

Within the low-lying spectrum of 10Be, multiple rotational bands are found, with strikingly different moments of inertia. A proposed interpretation has been that these bands variously represent triaxial rotation and prolate axially-deformed rotation. The bands are well-reproduced in ab initio no-core configuration interaction (NCCI) calculations. We use the calculated wave functions to elucidate the nuclear shapes underlying these bands, by examining the Elliott SU(3) symmetry content of these wave functions. The ab initio results support an interpretation in which the ground-state band, along with an accompanying K=2 side band, represent a triaxial rotor, arising from an SU(3) irreducible representation in the 0 hbar omega space. Then, the lowest excited K=0 band represents a prolate rotor, arising from an SU(3) irreducible representation in the 2 hbar omega space.