Resonant structure of 18Na and the N = 8 shell

L. Ni; Y. Jin; Z. H. Li; K. W. Brown; H. Hua; C. Y. Niu; A. K. Anthony; J. Barney; R. J. Charity; D. Dell'Aquila; J. M. Elson; J. Estee; G. Jhang; J. G. Li; W. G. Lynch; N. Michel; L. G. Sobotka; S. Sweany; F. C.E. Teh; A. Thomas; C. Y. Tsang; M. B. Tsang; S. M. Wang; H. Y. Wu; C. X. Yuan; K. Zhu

doi:10.1103/vktj-1wkr

Resonant structure of 18Na and the N = 8 shell

L. Ni
, Y. Jin
, Z. H. Li
, K. W. Brown
, H. Hua
, C. Y. Niu
, A. K. Anthony
, J. Barney
, R. J. Charity
, D. Dell'Aquila
, J. M. Elson
, J. Estee
, G. Jhang
, J. G. Li
, W. G. Lynch
, N. Michel
, L. G. Sobotka
, S. Sweany
, F. C.E. Teh
, A. Thomas

C. Y. Tsang, M. B. Tsang, S. M. Wang, H. Y. Wu, C. X. Yuan, K. Zhu

Department of Chemistry

Research output: Contribution to journal › Article › peer-review

2 Scopus citations

Abstract

The resonant structure of the proton-unbound nucleus ¹⁸Na has been studied via knockout reactions of a ²⁰Mg beam on a ⁹Be target. Three resonant states in ¹⁸Na are identified through the invariant-mass reconstruction of ¹⁷Ne+1p events, including the 1⁻¹ ground state with one-proton decay energy of 1.38(2) MeV. In comparison with the low-lying states in the mirror neutron-rich nucleus ¹⁸N, the 1⁻¹ ground state and 2⁻¹ excited state with π(1d_5/2 )³ ⊗ ν1p_1/2 configurations in ¹⁸Na likely correspond to different proton seniorities, ν = 3 and 1, respectively, while the 0⁻¹ and 1⁻² states with π(1d_5/2 )²(2s_1/2 ) ⊗ ν1p_1/2 configuration show obvious Thomas-Ehrman shifts.With the more-precise atomic mass of ¹⁸Na, the one-neutron separation energy S_n (¹⁹Na) = 20.31(2)MeV is derived. Based on the systematics of the differences in experimental one-neutron separation energy in the isotopic chains from Z = 9 to 12, the shell effects at N = 8 for proton-rich nuclei are discussed.

Original language	English
Journal	Physical Review C
Volume	112
Issue number	2
DOIs	https://doi.org/10.1103/vktj-1wkr
State	Published - Aug 22 2025

Access to Document

10.1103/vktj-1wkr

Cite this

@article{5fba630500344c5da97834595c2b6dc8,

title = "Resonant structure of 18Na and the N = 8 shell",

abstract = "The resonant structure of the proton-unbound nucleus 18Na has been studied via knockout reactions of a 20Mg beam on a 9Be target. Three resonant states in 18Na are identified through the invariant-mass reconstruction of 17Ne+1p events, including the 1−1 ground state with one-proton decay energy of 1.38(2) MeV. In comparison with the low-lying states in the mirror neutron-rich nucleus 18N, the 1−1 ground state and 2−1 excited state with π(1d5/2 )3 ⊗ ν1p1/2 configurations in 18Na likely correspond to different proton seniorities, ν = 3 and 1, respectively, while the 0−1 and 1−2 states with π(1d5/2 )2(2s1/2 ) ⊗ ν1p1/2 configuration show obvious Thomas-Ehrman shifts.With the more-precise atomic mass of 18Na, the one-neutron separation energy Sn (19Na) = 20.31(2)MeV is derived. Based on the systematics of the differences in experimental one-neutron separation energy in the isotopic chains from Z = 9 to 12, the shell effects at N = 8 for proton-rich nuclei are discussed.",

author = "L. Ni and Y. Jin and Li, \{Z. H.\} and Brown, \{K. W.\} and H. Hua and Niu, \{C. Y.\} and Anthony, \{A. K.\} and J. Barney and Charity, \{R. J.\} and D. Dell'Aquila and Elson, \{J. M.\} and J. Estee and G. Jhang and Li, \{J. G.\} and Lynch, \{W. G.\} and N. Michel and Sobotka, \{L. G.\} and S. Sweany and Teh, \{F. C.E.\} and A. Thomas and Tsang, \{C. Y.\} and Tsang, \{M. B.\} and Wang, \{S. M.\} and Wu, \{H. Y.\} and Yuan, \{C. X.\} and K. Zhu",

year = "2025",

month = aug,

day = "22",

doi = "10.1103/vktj-1wkr",

language = "English",

volume = "112",

journal = "Physical Review C",

issn = "2469-9985",

number = "2",

}

Ni, L, Jin, Y, Li, ZH, Brown, KW, Hua, H, Niu, CY, Anthony, AK, Barney, J, Charity, RJ, Dell'Aquila, D, Elson, JM, Estee, J, Jhang, G, Li, JG, Lynch, WG, Michel, N, Sobotka, LG, Sweany, S, Teh, FCE, Thomas, A, Tsang, CY, Tsang, MB, Wang, SM, Wu, HY, Yuan, CX & Zhu, K 2025, 'Resonant structure of 18Na and the N = 8 shell', Physical Review C, vol. 112, no. 2. https://doi.org/10.1103/vktj-1wkr

TY - JOUR

T1 - Resonant structure of 18Na and the N = 8 shell

AU - Ni, L.

AU - Jin, Y.

AU - Li, Z. H.

AU - Brown, K. W.

AU - Hua, H.

AU - Niu, C. Y.

AU - Anthony, A. K.

AU - Barney, J.

AU - Charity, R. J.

AU - Dell'Aquila, D.

AU - Elson, J. M.

AU - Estee, J.

AU - Jhang, G.

AU - Li, J. G.

AU - Lynch, W. G.

AU - Michel, N.

AU - Sobotka, L. G.

AU - Sweany, S.

AU - Teh, F. C.E.

AU - Thomas, A.

AU - Tsang, C. Y.

AU - Tsang, M. B.

AU - Wang, S. M.

AU - Wu, H. Y.

AU - Yuan, C. X.

AU - Zhu, K.

PY - 2025/8/22

Y1 - 2025/8/22

N2 - The resonant structure of the proton-unbound nucleus 18Na has been studied via knockout reactions of a 20Mg beam on a 9Be target. Three resonant states in 18Na are identified through the invariant-mass reconstruction of 17Ne+1p events, including the 1−1 ground state with one-proton decay energy of 1.38(2) MeV. In comparison with the low-lying states in the mirror neutron-rich nucleus 18N, the 1−1 ground state and 2−1 excited state with π(1d5/2 )3 ⊗ ν1p1/2 configurations in 18Na likely correspond to different proton seniorities, ν = 3 and 1, respectively, while the 0−1 and 1−2 states with π(1d5/2 )2(2s1/2 ) ⊗ ν1p1/2 configuration show obvious Thomas-Ehrman shifts.With the more-precise atomic mass of 18Na, the one-neutron separation energy Sn (19Na) = 20.31(2)MeV is derived. Based on the systematics of the differences in experimental one-neutron separation energy in the isotopic chains from Z = 9 to 12, the shell effects at N = 8 for proton-rich nuclei are discussed.

AB - The resonant structure of the proton-unbound nucleus 18Na has been studied via knockout reactions of a 20Mg beam on a 9Be target. Three resonant states in 18Na are identified through the invariant-mass reconstruction of 17Ne+1p events, including the 1−1 ground state with one-proton decay energy of 1.38(2) MeV. In comparison with the low-lying states in the mirror neutron-rich nucleus 18N, the 1−1 ground state and 2−1 excited state with π(1d5/2 )3 ⊗ ν1p1/2 configurations in 18Na likely correspond to different proton seniorities, ν = 3 and 1, respectively, while the 0−1 and 1−2 states with π(1d5/2 )2(2s1/2 ) ⊗ ν1p1/2 configuration show obvious Thomas-Ehrman shifts.With the more-precise atomic mass of 18Na, the one-neutron separation energy Sn (19Na) = 20.31(2)MeV is derived. Based on the systematics of the differences in experimental one-neutron separation energy in the isotopic chains from Z = 9 to 12, the shell effects at N = 8 for proton-rich nuclei are discussed.

UR - https://www.scopus.com/pages/publications/105020648811

U2 - 10.1103/vktj-1wkr

DO - 10.1103/vktj-1wkr

M3 - Article

AN - SCOPUS:105020648811

SN - 2469-9985

VL - 112

JO - Physical Review C

JF - Physical Review C

IS - 2

ER -

Resonant structure of 18Na and the N = 8 shell

Abstract

Access to Document

Other files and links

Fingerprint

Cite this