Multiscale physics of atomic nuclei from first principles

TL;DR

This paper presents a unified, non-perturbative framework rooted in chiral effective field theory to describe the multiscale physics of atomic nuclei, successfully reproducing experimental data and revealing shape coexistence and deformation near the neutron dripline.

Contribution

It introduces a novel approach combining symmetry-breaking and projection techniques to incorporate short- and long-range correlations from nuclear forces derived from QCD, enabling comprehensive nuclear structure predictions.

Findings

Accurately reproduces experimental data for neon isotopes

Reveals shape coexistence and deformation near the neutron dripline

Identifies key nuclear force components influencing deformation

Abstract

Atomic nuclei exhibit multiple energy scales ranging from hundreds of MeV in binding energies to fractions of an MeV for low-lying collective excitations. As the limits of nuclear binding is approached near the neutron- and proton driplines, traditional shell-structure starts to melt with an onset of deformation and an emergence of coexisting shapes. It is a long-standing challenge to describe this multiscale physics starting from nuclear forces with roots in quantum chromodynamics. Here we achieve this within a unified and non-perturbative framework that captures both short- and long-range correlations starting from modern nucleon-nucleon and three-nucleon forces from chiral effective field theory. The short-range correlations which accounts for the bulk of the binding energy is included within a symmetry-breaking framework, while long-range correlations (and fine details about the collective structure) are included via symmetry projection. Our calculations accurately reproduce available experimental data for low-lying collective states and the electromagnetic quadrupole transitions in $^{20-30}$Ne. We also reveal coexisting spherical and deformed shapes in $^{30}$Ne, which indicates the breakdown of the magic neutron number $N=20$ as the key nucleus $^{28}$O is approached, and we predict that the dripline nuclei $^{32,34}$Ne are strongly deformed. By developing reduced-order-models for symmetry-projected states, we perform a global sensitivity analysis and find that the subleading singlet S-wave contact and a pion-nucleon coupling strongly impact nuclear deformation in chiral effective-field-theory. The techniques developed in this work clarify how microscopic nuclear forces generate the multiscale physics of nuclei spanning collective phenomena as well as short-range correlations and allow to capture emergent and dynamical phenomena in finite fermion systems.