Nuclear fusion as a probe for octupole deformation in $^{224}$Ra

TL;DR

This paper explores how nuclear fusion reactions can be used to detect octupole deformation in nuclei, specifically in $^{224}$Ra, by analyzing differences in fusion barrier distributions.

Contribution

It demonstrates that measuring fusion barrier distributions can effectively distinguish between static octupole deformation and vibrational modes in nuclei.

Findings

Barrier distributions differ significantly for static deformation versus vibration.

$^{224}$Ra shows a large enough octupole deformation to produce observable effects.

Fusion measurements can clarify the presence of octupole deformation in nuclei.

Abstract

$\textit{Background}$: Nuclear fusion has been shown to be a perfect probe to study the different nuclear shapes. However, the possibility of testing octupole deformation of a nucleus with this tool has not been fully explored yet. The presence of a stactic octupole deformation in nuclei will enhanced a possible permanent electric dipole moment, leading to a possible demonstration of parity violation. $\textit{Purpose}$: To check whether static octupole deformation or octupole vibration in fusion give qualitatively different results so that both situations can be experimentally disentangled. $\textit{Method}$: Fusion cross sections are computed in the Coupled-Channels formalism making use of the Ingoing-Wave Boundary Conditions (IWBC) for the systems $^{16}$O+$^{144}$Ba and $^{16}$O+$^{224}$Ra. $\textit{Results}$: Barrier distributions of the two considered schemes show different patterns. For the $^{224}$Ra case, the octupole deformation parameter is large enough to create a sizeable difference. $\textit{Conclusions}$: The measurement of barrier distributions can be an excellent probe to clarify the presence of octupole deformation.