中国物理B ›› 2005, Vol. 14 ›› Issue (8): 1544-1548.doi: 10.1088/1009-1963/14/8/012

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Nuclear halo effect on nucleon capture reaction rates at stellar energies

周宏余1, 刘祖华2   

  1. (1)Key Laboratory of Beam Technology and Material Modification of Ministry of Education,Beijing Normal University, Beijing 100875, China; (2)Key Laboratory of Beam Technology and Material Modification of Ministry of Education,Beijing Normal University, Beijing 100875, China;China Institute of Atomic Energy, Beijing 102413,China
  • 收稿日期:2004-11-05 修回日期:2005-01-04 出版日期:2005-07-13 发布日期:2005-07-13
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant Nos 10075077, 10105016 and 10275092) and the National Key Basic Research of China (Grant No G200007400).

Nuclear halo effect on nucleon capture reaction rates at stellar energies

Liu Zu-Hua (刘祖华)ab, Zhou Hong-Yu (周宏余)a   

  1. a Key Laboratory of Beam Technology and Material Modification of Ministry of Education, Beijing Normal University, Beijing 100875, China; b China Institute of Atomic Energy, Beijing 102413, China
  • Received:2004-11-05 Revised:2005-01-04 Online:2005-07-13 Published:2005-07-13
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant Nos 10075077, 10105016 and 10275092) and the National Key Basic Research of China (Grant No G200007400).

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摘要： The capture cross sections at stellar energies are very difficult to measure directly. Hence, data are usually evaluated by using indirect methods or extrapolations from the experimental data obtained at the lowest possible energies. The asymptotic normalization coefficient (ANC) approach of the transfer reactions provides a reliable way for the determination of the capture cross sections at stellar energies. By virtue of its reliability, we have calculated the capture cross sections of the 10Be（n，γ）11Be reaction by using nuclear ANC method. 11Be is a well-known neutron halo nucleus with two weakly bound states.As a typical example, we have shown that the radiative cross sections for a nucleon captured into a halo state are obviously enhanced. The enormous enhancement of the capture cross section is just due to the large overlap of the incident neutron wave with the extended tail of the halo. The 10Be（n，γ）11Be capture reaction is involved in the inhomogeneous big-bang nucleosynthesis. We have evaluated its reaction rates at stellar energies with the nuclear ANC method.

关键词: nuclear halo, ANC method, direct capture, halo effects

Abstract: The capture cross sections at stellar energies are very difficult to measure directly. Hence, data are usually evaluated by using indirect methods or extrapolations from the experimental data obtained at the lowest possible energies. The asymptotic normalization coefficient (ANC) approach of the transfer reactions provides a reliable way for the determination of the capture cross sections at stellar energies. By virtue of its reliability, we have calculated the capture cross sections of the 10Be（n, $\gamma$）11Be reaction by using nuclear ANC method. 11Be is a well-known neutron halo nucleus with two weakly bound states.As a typical example, we have shown that the radiative cross sections for a nucleon captured into a halo state are obviously enhanced. The enormous enhancement of the capture cross section is just due to the large overlap of the incident neutron wave with the extended tail of the halo. The 10Be（n, $\gamma$）11Be capture reaction is involved in the inhomogeneous big-bang nucleosynthesis. We have evaluated its reaction rates at stellar energies with the nuclear ANC method.

Key words: nuclear halo, ANC method, direct capture, halo effects

中图分类号:  (Nucleon distributions and halo features)

  • 21.10.Gv
25.40.Lw (Radiative capture) 27.20.+n (6 ≤ A ≤ 19) 25.60.Dz (Interaction and reaction cross sections)