Determination of astrophysical ^7Be（p, γ）8B reaction rates from the ^7Li（d, p）^8Li reaction  

作　　者：DU XianChao GUO Bing LI ZhiHong PANG DanYang LI ErTao LIU WeiPing 

机构地区：[1]China Institute of Atomic Energy [2]School of Physics and Nuclear Energy Engineering,Beihang University [3]International Research Center for Nuclei and Particles in the Cosmos,Beihang University [4]College of Physics Science and Technology,Shenzhen University

出　　处：《Science China(Physics,Mechanics & Astronomy)》2015年第6期74-80,共7页中国科学：物理学、力学、天文学（英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant Nos.11321064,11490560,11475264,11375269 and11275272);the National Basic Research Program of China(Grant No.2013CB834406)

摘　　要：The ^7Be（p, γ）8B reaction plays a central role not only in the evaluation of solar neutrino fluxes but also in the evolution of the first stars. Study of this reaction requires the asymptotic normalization coefficient （ANC） for the virtual decay ^8Bg.s. → ^7Be ＋ p. By using the charge symmetry relation, we obtain this proton ANC with the single neutron ANC of ^8Lig.s.→^7Li ＋ n, which is determined with the distorted wave Born approximation （DWBA） and adiabatic distorted wave approximation （ADWA） analysis of the ^7Li（d, p）^8Li angular distribution. The astrophysical S-factors and reaction rates of the direct capture process in the 7Be（p, y）SB reaction are further deduced at energies of astrophysical relevance. The astrophysical S-factor at zero energy for direct capture, S 17（0）, is derived to be （19.9 ± 3.5） eV b in good agreement with the most recent recommended value. The contributions of the 1 ^＋ and 3^＋ resonances to the S-factor and reaction rate are also evaluated. The present result demonstrates that the direct capture dominates the ^7Be（p, γ）8B reaction in the whole temperature range. This work provides an independent examination to the current results of the ^7Be（p, γ）8B reaction.The7Be(p,γ)8B reaction plays a central role not only in the evaluation of solar neutrino fluxes but also in the evolution of the first stars.Study of this reaction requires the asymptotic normalization coefficient(ANC) for the virtual decay8 Bg.s.→7Be + p.By using the charge symmetry relation,we obtain this proton ANC with the single neutron ANC of8 Lig.s.→7Li + n,which is determined with the distorted wave Born approximation(DWBA) and adiabatic distorted wave approximation(ADWA) analysis of the7Li(d,p)8Li angular distribution.The astrophysical S-factors and reaction rates of the direct capture process in the7Be(p,γ)8B reaction are further deduced at energies of astrophysical relevance.The astrophysical S-factor at zero energy for direct capture,S17(0),is derived to be(19.9±3.5) e V b in good agreement with the most recent recommended value.The contributions of the1+and 3+resonances to the S-factor and reaction rate are also evaluated.The present result demonstrates that the direct capture dominates the7Be(p,γ)8B reaction in the whole temperature range.This work provides an independent examination to the current results of the7Be(p,γ)8B reaction.

关 键 词：^7Li（d p）^8Li Ed = 12 MeV DWBA analysis mirror system  ^7Be（p γ）8B astrophysical S-factors and reaction rates 

分 类 号：P14[天文地球—天体物理]