Ab initio study of the beryllium isotopes $^{7}$Be to $^{12}$Be

TL;DR

This paper uses ab initio nuclear lattice effective field theory to study beryllium isotopes, successfully matching experimental data and revealing complex nuclear structures and shapes through a novel, model-independent method.

Contribution

It introduces a new, model-independent approach to quantify nuclear shapes and uncovers complex structures like halos and molecular dynamics in beryllium isotopes.

Findings

Good agreement with experimental energies, radii, and electromagnetic properties.

Discovery of two-center cluster structures and neutron halos.

Identification of nuclear molecular dynamics such as π and σ orbitals.

Abstract

We present a systematic ab initio study of the low-lying states in beryllium isotopes from 7Be to 12Be using nuclear lattice effective field theory with the N3LO interaction. Our calculations achieve good agreement with experimental data for energies, radii, and electromagnetic properties. We introduce a novel, model-independent method to quantify nuclear shapes, uncovering a distinct pattern in the interplay between positive and negative parity states across the isotopic chain. By combining Monte Carlo sampling of the many-body density operator with a novel nucleon-grouping algorithm, the prominent two-center cluster structures, the emergence of one-neutron halo, complex nuclear molecular dynamics such as {\pi} orbital and {\sigma} orbital, emerge naturally.