Low-lying neutron unbound states in 12 Be
Low-lying neutron unbound states in 12 Be
复制标题
12 Be 中的低层中子游离态
DOI：
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发表时间：
2015
期刊：
影响因子：
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通讯作者：
S. Williams
中科院分区：
文献类型：
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作者：
J. Smith;T. Baumann;D. Bazin;J. Brown;S. Casarotto;P. DeYoung;N. Frank;J. Hinnefeld;M. Hoffman;Z. Jones;B. Kohley;B. Luther;N. Marks;J. Smith;A. Snyder;S. L. Spyrou;M. Stephenson;N. Thoennessen;S. J. Viscariello;Williams;M. Jones;Z. Kohley;B. Marks;N. Smith;J. Snyder;A. Spyrou;S. Stephenson;M. Thoennessen;N. Viscariello;S. Williams
测量了12Be中一个非束缚共振的中子衰变能量为1243±21 keV，衰变宽度为634±60 keV。这个状态是由71 MeV/u的13B束流入射到铍靶上的单质子去除反应形成的。通过测量子碎片与中子的重合，实现了共振的不变质量重建。尽管在2n分离能以上，但该态的衰变主要是通过发射1个中子到11Be来实现的，这使得双中子衰变通道分支比的上限小于5%。从共振的居群特征和衰减特征可以看出，该态不能与先前观测到的4580±5 keV的态相对应。
The neutron decay of an unbound resonance in 12Be has been measured at 1243 ± 21 keV decay energy with a width of 634 ± 60 keV. This state was populated with a one-proton removal reaction from a 71 MeV/u 13B beam incident upon a beryllium target. The invariant mass reconstruction of the resonance was achieved by measuring the daughter fragment in coincidence with neutrons. Despite being above the 2n separation energy, the state decays predominantly by the emission of one neutron to 11Be, setting an upper limit on the branching ratio for the two-neutron decay channel to 10Be of less than 5%. From the characteristics of the population and decay of the resonance, it is concluded that this state cannot correspond to the previously observed state at 4580 ± 5 keV.