Ab initio calculations with a new local chiral N3LO nucleon-nucleon force

TL;DR

This paper demonstrates that a new local chiral N3LO nucleon-nucleon interaction can accurately reproduce low-lying spectra and shell evolution in p-shell nuclei and oxygen isotopes within ab initio calculations, highlighting its potential as an alternative to nonlocal interactions.

Contribution

The study introduces and applies a novel local chiral N3LO NN interaction in ab initio nuclear calculations, showing its effectiveness in reproducing nuclear spectra and shell features.

Findings

Accurately reproduces spectra of p-shell nuclei, especially 10B.

Successfully predicts the neutron drip line at 24O.

Reproduces subshell closures at N=14 and 16, with stronger shell gaps.

Abstract

Ab initio calculations have achieved remarkable success in nuclear structure studies. Numerous works highlight the pivotal role of three-body forces in nuclear ab initio calculations. Concurrently, efforts have been made to replicate these calculations using only realistic nucleon-nucleon (NN) interactions. A novel local chiral next-to-next-to-next-to-leading order (N3LO) NN interaction, distinct due to its weaker tensor force, has recently been established. This paper applies this local NN interaction in ab initio frameworks to calculate the low-lying spectra of p-shell light nuclei, particularly 10B, ground-state energies and shell evolution in oxygen isotopes. Results are compared with calculations utilizing nonlocal chiral N3LO NN and chiral NN +3N interactions. The ab initio calculations with the local N N potential accurately describe the spectra of p-shell nuclei, notably the 10B. Additionally, the neutron drip line for oxygen isotopes, with 24O as the drip line nucleus, is accurately reproduced in ab initio calculations with the local NN interaction. Calculations with the local NN interaction also reproduce the subshell closure at N = 14 and 16, albeit with a stronger shell gap compared to experimental data. However, the calculated charge radii based on the local NN interaction are underestimated compared with experimental data, which is similar to results from the nonlocal NN interaction. Consequently, the present ab initio calculations further indicate significant spin-orbit splitting effects with the new local NN potential, suggesting that 3N forces remain an important consideration.