利用8He(p, d)7He 和8He(p, t)6He反应研究8He的基态.docVIP

利用8He(p, d)7He 和8He(p, t)6He反应研 究8He的基态 2 6 d)7Heg.s 和8He(p, t)6He2+反应的微分截面。实验结果与基于扭曲波玻恩近似框架的理论计算 结果做了对比。结果表明在8He的基态波函数中，(1p3/2)2(1p1/2)2的组态可能有重要的贡献。 团簇结构8He = 5H + 3H也不容忽视。 关键词：核物理，转移反应，谱因子，基态 中图分类号： O57 Study on the 8He ground state via 8He(p, d)7He and 8He(p, t)6He reaction at 82.3 MeV/nucleon J L Lou1, Y L Ye1, D Y Pang1, Z X Cao1, D X Jiang1 1 2 School of Physics and State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing 100871 School of Physics and Nuclear Energy Engineering, Beihang University, Beijing 100191 Abstract: The di?erential cross sections for reactions 8He(p, d)7Heg.s and 8He(p, t)6He2+ were measured by the coincidence of d + 6He and t + 4He in a wide angular range from 15 to 130 degree in the center-of-mass system. The cross sections of the 8He(p, t)6Heg.s. reaction were extremely lower than that of 8He(p, t)6He2+ reaction, and was not obtained from the present data. The experimental results were compared to the preliminary theoretical calculations in the frame of adiabatic distorted-wave approximation with the code Fresco. The results show that the con?guration of (1p3/2)2(1p1/2)2 may have some probability in the ground state wave function of 8He. The cluster structure of 8He = 5H + 3H could not be neglected. Key words: nuclear physics, transfer reaction, spectroscopic factor, ground state. 0  Introduction The nucleus 8He has the largest neutron to proton ratio among all the known particle- stable nucleus, exhibiting a neutron halo or thick neutron skin, and is an excellent candidate for the test of nuclear structure models. However, the structure of its ground state is still controversial. Theoretically, asymmetry molecule dynamics (AMD) calculation shows that the ground state of 8He has both a j ? j coupling feature (4He + 4n) and a L ? S coupling feature (4He + 2n + 2n) [1], but the cluster orbital shell model approximation (COSMA) model suggests that the dominant con?guration is an alpha particle core