Narrow Results

This article is composed of three subjects. First, the relation between the method of continuum-discretized coupled channels (CDCC) and the Faddeev theory is clarified to show the validity of CDCC. Second, CDCC is applied to four-body reactions such as (⁶He, nn⁴He) as an example of recent progress in CDCC. Third, we propose a microscopic version of CDCC in which a localized form of the microscopic nucleon-nucleus optical potential is used as an input of CDCC calculation instead of the phenomenological optical potential commonly used. The validity of the Brieva-Rook localization is shown for the proton scattering in a wide incident-energy range.

We present a new method of smoothing discrete breakup cross sections calculated by the method of continuum-discretized coupled-channels. In the four-body breakup reaction of ¹²C(⁶He, nn⁴He) at E_in = 229.8 MeV, the continuous breakup cross section is evaluated as a function of the excitation energy of ⁶He. Convergence of the cross section with respect to extending the modelspace is also confirmed.

We present analyses of breakup effects of ⁶He on the elastic scattering by the continuum-discretized coupled-channels method, in which the reaction system is described as a four-body model, n+n+⁴He+target. In this analysis, three-body breakup continuum of ⁶He is discretized by daiagonalizing the internal Hamiltonian of ⁶He in a space spanned by the Gaussian basis functions. The calculated elastic cross sections are in good agreement with the experimental data, which shows that nuclear and Coulomb breakup effects are significant.

In this talk, we propose applying the complex-scaling method to CDCC, where the internal coordinate and momentum of projectile nucleus are complex-scaled. We show that the continuous S matrix element of breakup reaction is obtained without smoothing function.

Rare isotopes are most often studied through nuclear reactions. Nuclear reactions can be used to obtain detailed structure information but also in connection to astrophysics to determine specific capture rates. In order to extract the desired information it is crucial to have a reliable framework that describes the reaction process accurately. A few recent developments for transfer and breakup reactions will be presented. These include recent studies on the reliability of existing theories as well as effort to reduce the ambiguities in the predicted observables.