Neutron occupancy of the 0d5/2 orbital and the N=16 shell closure in 24O

K. Tshoo; Y. Satou; C. A. Bertulani; H. Bhang; S. Choi; T. Nakamura; Y. Kondo; S. Deguchi; Y. Kawada; Y. Nakayama; K. N. Tanaka; N. Tanaka; Y. Togano; N. Kobayashi; N. Aoi; M. Ishihara; T. Motobayashi; H. Otsu; H. Sakurai; S. Takeuchi; K. Yoneda; F. Delaunay; J. Gibelin; F. M. Marqués; N. A. Orr; T. Honda; T. Kobayashi; T. Sumikama; Y. Miyashita; K. Yoshinaga; M. Matsushita; S. Shimoura; D. Sohler; J. W. Hwang; T. Zheng; Z. H. Li; Z. X. Cao

doi:10.1016/j.physletb.2014.10.033

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arXiv · 1410.7162

Neutron occupancy of the 0d5/2 orbital and the N=16 shell closure in 24O

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Abstract

One-neutron knockout from 24O leading to the first excited state in 23O has been measured for a proton target at a beam energy of 62 MeV/nucleon. The decay energy spectrum of the neutron unbound state of 23O was reconstructed from the measured four momenta of the 22O fragment and emitted neutron. A sharp peak was found at Edecay=50$\pm$3 keV, corresponding to an excited state in 23O at 2.78$\pm$0.11 MeV, as observed in previous measurements. The longitudinal momentum distribution for this state was consistent with d -wave neutron knockout, providing support for a Jπ assignment of 5/2+. The associated spectroscopic factor was deduced to be C2S(0d5/2)=4.1$\pm$0.4 by comparing the measured cross section (View the MathML source) with a distorted wave impulse approximation calculation. Such a large occupancy for the neutron 0d5/2 orbital is in line with the N=16 shell closure in 24O.

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K. Tshoo, Y. Satou, C. A. Bertulani, H. Bhang, S. Choi, T. Nakamura, Y. Kondo, S. Deguchi, Y. Kawada, Y. Nakayama, K. N. Tanaka, N. Tanaka, Y. Togano, N. Kobayashi, N. Aoi, M. Ishihara, T. Motobayashi, H. Otsu, H. Sakurai, S. Takeuchi, K. Yoneda, F. Delaunay, J. Gibelin, F. M. Marqués, N. A. Orr, T. Honda, T. Kobayashi, T. Sumikama, Y. Miyashita, K. Yoshinaga, M. Matsushita, S. Shimoura, D. Sohler, J. W. Hwang, T. Zheng, Z. H. Li, Z. X. Cao. 2014-10-27. Neutron occupancy of the 0d5/2 orbital and the N=16 shell closure in 24O. https://doi.org/10.1016/j.physletb.2014.10.033

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