Properties of the 7He ground state from 8He neutron knockout
Properties of the 7He ground state from 8He neutron knockout
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DOI：
10.1016/j.physletb.2009.07.044
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发表时间：
2009-08
影响因子：
4.4
通讯作者：
Y. Aksyutina;H. Johansson;T. Aumann;K. Boretzky;M. Borge;A. Chatillon;L. Chulkov;D. Cortina-Gil;U. D. Pramanik;H. Emling;C. Forssén;H. Fynbo;H. Geissel;G. Ickert;B. Jonson;R. Kulessa;C. Langer;M. Lantz;T. LeBleis;A. Lindahl;K. Mahata;M. Meister;G. Münzenberg;T. Nilsson;G. Nyman;R. Palit;S. Paschalis;W. Prokopowicz;R. Reifarth;A. Richter;K. Riisager;G. Schrieder;H. Simon;K. Sümmerer;O. Tengblad;H. Weick;M. Zhukov
中科院分区：
文献类型：
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作者：
Y. Aksyutina;H. Johansson;T. Aumann;K. Boretzky;M. Borge;A. Chatillon;L. Chulkov;D. Cortina-Gil;U. D. Pramanik;H. Emling;C. Forssén;H. Fynbo;H. Geissel;G. Ickert;B. Jonson;R. Kulessa;C. Langer;M. Lantz;T. LeBleis;A. Lindahl;K. Mahata;M. Meister;G. Münzenberg;T. Nilsson;G. Nyman;R. Palit;S. Paschalis;W. Prokopowicz;R. Reifarth;A. Richter;K. Riisager;G. Schrieder;H. Simon;K. Sümmerer;O. Tengblad;H. Weick;M. Zhukov
用240 MeV/u8He束流在液氢靶上进行的中子击穿反应中产生的非束缚核7He，已经在GSI的阿拉丁岛装置上进行了实验研究。从R矩阵分析得到了7He的共振参数以及基态6He(0+)+n组态的光谱因子。光谱因子为0.61，表明7He不是纯单粒子态。对~6He在碳靶中的中子敲除反应的~5He数据的分析表明，在α+n相对能谱中存在低能的S波分量。在本实验中，从碳靶的~8He中子击穿数据中观察到的~7He可能的低激发态，暂时解释为Iπ=1/2−态。根据靶标依赖性或相对论能量下不同的反应机制，讨论了两种敲除反应中~7He共振形状差异的可能解释。
The unbound nucleus7He, produced in neutron-knockout reactions with a 240 MeV/u8He beam in a liquid-hydrogen target, has been studied in an experiment at the ALADIN-LAND setup at GSI. From an R-matrix analysis the resonance parameters for7He as well as the spectroscopic factor for the6He(0+)+n configuration in its ground-state have been obtained. The spectroscopic factor is 0.61 confirming that7He is not a pure single-particle state. An analysis of5He data from neutron-knockout reactions of6He in a carbon target reveals the presence of an s-wave component at low energies in the α+n relative energy spectrum. A possible low-lying exited state in7He observed in neutron knockout data from8He in a carbon target and tentatively interpreted as a Iπ=1/2−state, could not be observed in the present experiment. Possible explanations of the shape difference between the7He resonance obtained in the two knockout reactions are discussed in terms of target-dependence or different reaction mechanisms at relativistic energies.