Spectroscopic study of neutron shell closures via nucleon transfer in the near-dripline nucleus 23O
Spectroscopic study of neutron shell closures via nucleon transfer in the near-dripline nucleus 23O
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DOI：
10.1103/physrevlett.98.102502
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发表时间：
2007-03-09
影响因子：
8.6
通讯作者：
Yanagisawa, Y.
中科院分区：
文献类型：
--
作者：
Elekes, Z.;Dombradi, Zs.;Yanagisawa, Y.
用O-22（d，p）O-23（*）-> O-22+n过程测量了O-23中的中子单粒子能量。共振态的能量分别为4.00（2）MeV和5.30（4）MeV。通过与壳模型计算结果的比较，第一激发态可以归属于nu d（3/2）单粒子态。在nu s（1/2）和nu d（3/2）态之间测量到的4.0 MeV能量差给出了N=16的壳能隙的大小，这与最近的USD 05（2005年的“通用”sd）壳模型计算一致，并且足够大以解释比A=24重的氧同位素的未结合性质。在5.3 MeV处检测到的共振可以被分配到sd壳模型空间之外的状态。其能量对应于类似于1.3 MeV大小的N=20壳层间隙，因此，N=20壳层闭合在Z=8处消失，与使用SDPF-M相互作用的Monte Carlo壳层模型计算一致。
Neutron single particle energies have been measured in O-23 using the O-22(d,p)O-23(*)-> O-22+n process. The energies of the resonant states have been deduced to be 4.00(2) MeV and 5.30(4) MeV. The first excited state can be assigned to the nu d(3/2) single particle state from a comparison with shell model calculations. The measured 4.0 MeV energy difference between the nu s(1/2) and nu d(3/2) states gives the size of the N=16 shell gap which is in agreement with the recent USD05 ("universal" sd from 2005) shell model calculation, and is large enough to explain the unbound nature of the oxygen isotopes heavier than A=24. The resonance detected at 5.3 MeV can be assigned to a state out of the sd shell model space. Its energy corresponds to a similar to 1.3 MeV sized N=20 shell gap, therefore, the N=20 shell closure disappears at Z=8 in agreement with Monte Carlo shell model calculations using SDPF-M interaction.