Details

Autor(en) / Beteiligte

• Fernandez-Dominguez, B.
• Grand Accelerateur National d'Ions Lourdes, 14076 Caen Cedex 5
• Laboratoire de Physique Corpusculaire Caen, Ecole Nationale Superieure d'Ingenieurs de Caen, Universite de Caen, Centre National de la Recherche Scientifique and Institute National de Physique Nucleaire et de Physique des Particles, 14050 Caen
• Thomas, J. S.
• Catford, W. N.
• Brown, S. M.
• Patterson, N.
• Wilson, G. L.
• Delaunay, F.
• Orr, N. A.
• Achouri, N. L.
• Al Falou, H.
• Leprince, A.
• Rejmund, M.
• Force, C.
• France, G. de
• Navin, A.
• Sorlin, O.
• Labiche, M.
• Lemmon, R. C.
• Chartier, M.
• Pietras, B.

Titel

Emergence of the N=16 shell gap in {sup 21}O

Ist Teil von

• Physical review. C, Nuclear physics, 2011-07, Vol.84 (1)

Ort / Verlag

United States

Erscheinungsjahr

2011

Quelle

PROLA - Physical Review Online Archive

Beschreibungen/Notizen

• The spectroscopy of {sup 21}O has been investigated using a radioactive {sup 20}O beam and the (d,p) reaction in inverse kinematics. The ground and first excited states have been determined to be J{sup {pi}=}5/2{sup +} and 1/2{sup +}, respectively. Two neutron unbound states were observed at excitation energies of 4.77(10) and 6.17(11) MeV. The spectroscopic factor deduced for the lower of these, interpreted as a 3/2{sup +} level, reveals a relatively pure (60%) 0d{sub 3/2} single-particle configuration, in good agreement with shell-model calculations that predict {sup 26}O to be unbound. The large energy difference between the 3/2{sup +} and 1/2{sup +} states is indicative of the emergence of the N=16 shell gap, which is estimated to be 5.1(11) MeV. For the higher-lying resonance, which has a character consistent with a spin-parity assignment of 3/2{sup +} or 7/2{sup -}, a 0.71(22) branching ratio to the first 2{sup +} state in {sup 20}O has been observed.