Coulomb breakup effects on the elastic cross section of He-6 + Bi-209 scattering near Coulomb barrier energies

We accurately analyze the {sup 6}He+{sup 209}Bi scattering at 19 and 22.5 MeV near the Coulomb barrier energy, using the continuum-discretized coupled-channels (CDCC) method based on the n+n+ {sup 4}He+{sup 209}Bi four-body model. The three-body breakup continuum of {sup 6}He is discretized by diagonalizing the internal Hamiltonian of {sup 6}He in a space spanned by the Gaussian basis functions. The calculated elastic and total reaction cross sections are in good agreement with the experimental data, whereas the CDCC calculation based on the dineutron model of {sup 6}He, that is, the {sup 2}n+ {sup 4}He+{sup 209}Bi three-body model, does not reproduce the data.