Determination of the n=16 shell closure at the oxygen drip line

被引：153

作者：

Hoffman, C. R. ^{[1
]}

Baumann, T. ^{[2
]}

Bazin, D. ^{[2
]}

Brown, J. ^{[3
]}

Christian, G. ^{[2
,4
]}

DeYoung, P. A.

Finck, J. E. ^{[6
]}

Frank, N. ^{[2
,4
]}

Hinnefeld, J. ^{[7
]}

Howes, R. ^{[8
]}

Mears, P. ^{[5
]}

Mosby, E. ^{[9
]}

Mosby, S. ^{[9
]}

Reith, J.

Rizzo, B. ^{[8
]}

Rogers, W. F. ^{[9
]}

Peaslee, G. ^{[5
]}

Peters, W. A. ^{[2
]}

Schiller, A. ^{[2
]}

Scott, M. J. ^{[6
]}

Tabor, S. L. ^{[1
]}

Thoennessen, M. ^{[2
,4
]}

Voss, P. J. ^{[6
]}

Williams, T. ^{[3
]}

机构：

[1] Florida State Univ, Dept Phys, Tallahassee, FL 32303 USA

[2] Michigan State Univ, Natl Superconducting Cyclotron Lab, E Lansing, MI 48824 USA

[3] Wabash Coll, Dept Phys, Crawfordsville, IN 47933 USA

[4] Michigan State Univ, Dept Phys & Astron, E Lansing, MI 48824 USA

[5] Hope Coll, Dept Phys, Holland, MI 49423 USA

[6] Cent Michigan Univ, Dept Phys, Mt Pleasant, MI 48859 USA

[7] Indiana Univ S Bend, Dept Phys & Astron, South Bend, IN 46634 USA

[8] Marquette Univ, Dept Phys, Milwaukee, WI 53201 USA

[9] Westmont Coll, Dept Phys, Santa Barbara, CA 93108 USA

来源：

PHYSICAL REVIEW LETTERS | 2008年 / 100卷 / 15期

关键词：

D O I：

10.1103/PhysRevLett.100.152502

中图分类号：

O4 [物理学];

学科分类号：

0702 ;

摘要：

The neutron unbound ground state of (25)O (Z=8, N=17) was observed for the first time in a proton knockout reaction from a (26)F beam. A single resonance was found in the invariant mass spectrum corresponding to a neutron decay energy of 770(-10)(+20) keV with a total width of 172(30) keV. The N=16 shell gap was established to be 4.86(13) MeV by the energy difference between the nu 1s(1/2) and nu 0d(3/2) orbitals. The neutron separation energies for (25)O agree with the calculations of the universal sd shell model interaction. This interaction incorrectly predicts an (26)O ground state that is bound to two-neutron decay by 1 MeV, leading to a discrepancy between the theoretical calculations and experiment as to the particle stability of (26)O. The observed decay width was found to be on the order of a factor of 2 larger than the calculated single-particle width using a Woods-Saxon potential.

引用

页数：5

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