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arXiv · 1108.2680

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.

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BibTeXRIS

J. D. Holt, J. Menendez, A. Schwenk. 2013-03-19. Chiral three-nucleon forces and bound excited states in neutron-rich oxygen isotopes. https://doi.org/10.1140/epja%2Fi2013-13039-2

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