Description of 8B decomposition reaction by four-body CDCC

It is decided that the sun neutrino problem is originated by neutrino oscillation. Accordingly, the reaction cross section (S17) of 8B has to be determined less than 5% error. S17 is determined by three kinds of methods such as the CDCC (Continuum-Discretized Coupled-Channels) method, ANC (Asymptotic Normalization Coefficient) method and the direct determination method. On 8B + p → p + 7Be + p, the effectiveness of ANC method is investigated. The results showed the ANC did not work the function. Accordingly, the inside state of 8Be contributed largely to the reaction. Description of the inside state of 8Be needs three-body such as p + α + 3He. It is concluded that 8B is described by three-body and analyzed by four-body system including target. That is the analysis of three-body reaction has to be calculated by the four-body CDCC. (S.Y.)