Generator coordinate method for nuclear octupole excitations: status and perspectives

TL;DR

This review discusses the use of the Generator Coordinate Method combined with quantum-number projections to study nuclear octupole excitations, covering recent advances, phenomena, and implications for fundamental physics.

Contribution

It provides a comprehensive overview of recent developments in applying GCM with symmetry restoration to nuclear octupole phenomena and explores future research directions.

Findings

Enhanced understanding of octupole excitation spectra and transition rates.

Identification of nucleon clustering phenomena in light nuclei.

Insights into octupole deformation effects on nuclear Schiff moments.

Abstract

Strong octupole correlations have been observed in the low-lying states of atomic nuclei across various mass regions. In this review, we provide an overview of Beyond Mean-Field (BMF) studies of nuclear octupole collective motions with Generator Coordinate Method (GCM) in combination with quantum-number projections that are implemented to restore the broken symmetries in nuclear mean-field states. We highlight recent developments within this framework and their applications to excitation spectra and electromagnetic transition rates in octupole-shaped nuclei and hypernuclei. We discuss the novel phenomena of nucleon clustering in light nuclei. Additionally, we explore the phase transition from octupole vibrations to rotational motions as spin increases in heavy nuclei. Lastly, we examine the status and future prospects of studies on octupole deformation effects in nuclear Schiff moments. These studies, along with the upper limits of atomic Electric Dipole Moment (EDM), impose stringent constraints on beyond-standard-model time-reversal-violating nucleon-nucleon interactions.