Complete set of bound negative-parity states in the neutron-rich 18N nucleus

Abstract

High-resolution gamma-ray spectroscopy of 18N is performed with the Advanced GAmma Tracking Array AGATA, following deep-inelastic processes induced by an 18O beam on a 181Ta target. Six states are newly identified, which together with the three known excitations exhaust all negative-parity excited states expected in 18N below the neutron threshold. Spin and parities are proposed for all located states on the basis of decay branchings and comparison with large-scale shell-model calculations performed in the p-sd space, with the YSOX interaction. Of particular interest is the location of the 0^-_1 and 1^-_2 excitations, which provide strong constrains for cross-shell p-sd matrix elements based on realistic interactions, and help to simultaneously reproduce the ground and first-excited states in 16N and 18N, for the first time. Understanding the 18N structure may also have significant impact on neutron-capture cross-section calculations in r-process modeling including light neutron-rich nuclei.

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Cited by in corpus (4)

• Fast trajectory reconstruction techniques for the large acceptance magnetic spectrometer VAMOS++
• High-precision spectroscopy of ${}^{20}$O benchmarking ab-initio calculations in light nuclei
• Gamow shell model study of the 17Ne(p, p) reaction and of isospin symmetry breaking in 18Na
• Study of the Isomeric State in ${}^{16}$N Using the ${}^{16}$N${}^{g,m}$($d$,${}^3$He) Reaction