Nuclear astrophysics studies with the method of continuum-discretized coupled-channels

The method of continuum-discretized coupled-channels (CDCC) is applied to two nuclear astrophysics studies. One is the determination of the astrophysical factor S₁₇(0) for the ⁷Be(p,γ)⁸B reaction from the analysis of ⁸B breakup by ²⁰⁸Pb at 52 A MeV. We obtain S₁₇(0) = 20.9^+2.0_-1.9 eV b, which is significantly larger than the previous one, S₁₇(0) = 18.9±1.8 eV b, determined from an analysis with the virtual photon theory. The difference between the two values is found to be due to the contributions from nuclear breakup and higher-order processes. The other application of CDCC is the re-evaluation of the triple-α reaction rate by directly solving the three-body Schrödinger equation. The resonant and nonresonant processes are treated on the same footing. An accurate description of the α-α nonresonant states significantly quenches the Coulomb barrier between the first two α-particles and the third α-particle. Consequently, the α-α nonresonant continuum states give a markedly larger contribution at low temperatures than that reported in previous studies. We find an increase in triple-α reaction rate by 26 orders of magnitude around 10⁷ K compared with the rate of NACRE.