Halo Nuclei from Ab Initio Nuclear Theory

TL;DR

This paper introduces the no-core shell model with continuum (NCSMC), an ab initio method for accurately describing both bound and unbound states in light halo nuclei using chiral nuclear interactions.

Contribution

The development and application of the NCSMC approach to predict structure and reactions of halo nuclei, testing chiral forces against experimental data.

Findings

Successfully described weakly bound states and resonances of exotic halo nuclei.

Predicted properties of $^{15}$C and its production in capture reactions.

Explored the structure of $^6$He and $^{10}$Be with halo characteristics.

Abstract

A realistic description of halo nuclei, characterized by low-lying breakup thresholds, requires a proper treatment of continuum effects. We have developed an ab initio approach, the no-core shell model with continuum (NCSMC), capable of describing both bound and unbound states in light nuclei in a unified way. With chiral two- and three-nucleon interactions as the only input, we can predict structure and dynamics of halo and other light nuclei and, by comparing to available experimental data, test the quality of chiral nuclear forces. We review NCSMC calculations of weakly bound states and resonances of exotic halo nuclei $^6$He, $^8$B, $^{11}$Be, and $^{15}$C. For the latter, we discuss its production in the capture reaction $^{14}$C(n,$\gamma$)$^{15}$C. We highlight challenges of a description of $^6$He as a Borromean n-n-$^4$He system. Finally, we present calculations of excited states in $^{10}$Be exhibiting a one-neutron halo structure and a large scale no-core shell model investigation of $^{11}$Li as a precursor of a full n-n-$^9$Li NCSMC study.