Chiral three-nucleon forces and bound excited states in neutron-rich oxygen isotopes
Abstract
We study the spectra of neutron-rich oxygen isotopes based on chiral two- and three-nucleon interactions. First, we benchmark our many-body approach by comparing ground-state energies to coupled-cluster results for the same two-nucleon interaction, with overall good agreement. We then calculate bound excited states in 21,22,23O, focusing on the role of three-nucleon forces, in the standard sd shell and an extended sdf7/2p3/2 valence space. Chiral three-nucleon forces provide important one- and two-body contributions between valence neutrons. We find that both these contributions and an extended valence space are necessary to reproduce key signatures of novel shell evolution, such as the N = 14 magic number and the low-lying states in 21O and 23O, which are too compressed with two-nucleon interactions only. For the extended space calculations, this presents first work based on nuclear forces without adjustments. Future work is needed and open questions are discussed.
Keywords
Cite
@article{arxiv.1108.2680,
title = {Chiral three-nucleon forces and bound excited states in neutron-rich oxygen isotopes},
author = {J. D. Holt and J. Menendez and A. Schwenk},
journal= {arXiv preprint arXiv:1108.2680},
year = {2013}
}
Comments
6 pages, 4 figures, published version