Approaching the Island of Inversion: 34P
Approaching the Island of Inversion: 34P
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接近反转岛：34P
DOI：
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发表时间：
2009
期刊：
影响因子：
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通讯作者：
A. Volya
中科院分区：
文献类型：
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作者：
P. Bender;C. Hoffman;M. Wiedeking;J. Allmond;L. Bernstein;Jason T. Harke;D. Bleuel;R. Clark;P. Fallon;B. Goldblum;T. Hinners;H. Jeppesen;Sangjin Lee;I. Lee;S. R. Lesher;A. Macchiavelli;M. McMahan;D. Morris;M. Perry;L. Phair;N. Scielzo;S. Tabor;V. Tripathi;A. Volya
佛罗里达州立大学和劳伦斯伯克利国家实验室利用能量为 20、24、25、30 和 44 MeV 的 {sup 18}O({sup 18}O,pn) 反应研究了 {sup 34}P 中的 Yrast 态。扩展了能级方案，测量了γ射线角分布，并通过检测与一根或多根γ射线一致的衰变质子，用多普勒频移衰减方法推断了寿命。结果提供了接近“反转岛”的结构演化的更清晰图像，特别是随着接近反转的中子数增加，一粒子和两粒子空穴（ph）态的能量如何下降。然而，最低的几个状态与纯 sd 壳模型预测的一致性表明，{sup 34}P 的能级方案本身并未反转。相反，积累的证据表明 1-ph 态从 2.3 MeV 开始。最低 2-ph 态的一个很好的候选点是 6236 keV，略低于中子分离能 6291 keV。使用 WBP 相互作用的小修改进行的壳模型计算很好地再现了负宇称、1-ph 状态。
Yrast states in {sup 34}P were investigated using the {sup 18}O({sup 18}O,pn) reaction at energies of 20, 24, 25, 30, and 44 MeV at Florida State University and at Lawrence Berkeley National Laboratory. The level scheme was expanded, {gamma}-ray angular distributions were measured, and lifetimes were inferred with the Doppler-shift attenuation method by detecting decay protons in coincidence with one or more {gamma} rays. The results provide a clearer picture of the evolution of structure approaching the 'island of inversion,' particularly how the one- and two-particle-hole (ph) states fall in energy with increasing neutron number approaching inversion. However, the agreement of the lowest few states with pure sd shell model predictions shows that the level scheme of {sup 34}P is not itself inverted. Rather, the accumulated evidence indicates that the 1-ph states start at 2.3 MeV. A good candidate for the lowest 2-ph state lies at 6236 keV, just below the neutron separation energy of 6291 keV. Shell model calculations made using a small modification of the WBP interaction reproduce the negative-parity, 1-ph states rather well.