Title

Disappearance of the N=14 Shell

Authors

M J. Strongman
A Spyrou
C R. Hoffman
T Baumann
D Bazin
J Brown
Paul A. DeYoung, Hope CollegeFollow
J E. Finck
N Frank
S Mosby
W F. Rogers
Graham F. Peaslee, Hope CollegeFollow
W A. Peters
A Schiller
S L. Tabor
M Thoennessen

Document Type

Article

Publication Date

2009

Publication Source

Phys. Rev. C80

First Page

021302(R)

Publisher

American Physical Society

Abstract

An excited state of (22)N unbound with respect to neutron emission was observed in a stripping reaction from a 85 MeV/nucleon (26)F beam. The observed decay energy of 650(50) keV places the level, which is interpreted to be the first 3(-) state, at an excitation energy of 1.93(22) MeV. Together with the previously measured bound states of (22)N, reduction of the N=14 shell gap compared to less neutron-rich nitrogen isotopes at the neutron dripline is observed. Based on the magnitude of the reduction of the shell gap for (22)N, a disappearance of the gap and even a level inversion of the nu 1s(1/2) and the nu 0d(5/2) levels in the neutron-unbound nucleus (21)C seems likely.

Recommended Citation

Published in: Phys. Rev. C80, January 1, 2009, pages 021302(R)-. Copyright © 2009 American Physical Society. The final published version is available at: http://dx.doi.org/10.1103/PhysRevC.80.021302