Determination of S-17 from B-8 breakup by means of the method of continuum-discretized coupled channels

作者：Ogata K^*; Hashimoto S; Iseri Y; Kamimura M; Yahiro M

来源：Physical Review C, 2006, 73(2): 024605.

DOI：10.1103/PhysRevC.73.024605

The astrophysical factor for Be-7(p,gamma)B-8 at zero energy, S-17(0), is determined from an analysis of Pb-208(B-8, p+Be-7)Pb-208 at 52 MeV/nucleon by means of the method of continuum-discretized coupled channels (CDCC) taking account of all nuclear and Coulomb breakup processes. The asymptotic normalization coefficient (ANC) method is used to extract S-17(0) from the calculated breakup cross section. The main result of the present paper is S-17(0)=20.9(-1.9)(+2.0) eV b. The error consists of 8.4% experimental systematic error and the error due to the ambiguity in the s-wave p-Be-7 scattering length. This value of S-17(0) differs from the one extracted with the first-order perturbation theory including Coulomb breakup by dipole transitions: 18.9 +/- 1.8 eV b. It turns out that the difference is due to the inclusion of the nuclear and Coulomb-quadrupole transitions and multistep processes of all-order in the present work. The p-Be-7 interaction potential used in the CDCC calculation is also used in the ANC analysis of Be-7(p,gamma)B-8. The value of S-17(0)=21.7(-0.55)(+0.62) eV b obtained is consistent with the previous one obtained from a precise measurement of the p-capture reaction cross section extrapolated to zero incident energy, S-17(0)=22.1 +/- 0.6 (expt) +/- 0.6 (theo) eV b, where (theo) stands for the error in the extrapolation. Thus, the agreement between the values of S-17(0) obtained from direct Be-7(p,gamma)B-8 and indirect B-8-breakup measurements is significantly improved.

• 出版日期2006-2