Microscopic description of fusion hindrance in symmetric Ni + Ni and asymmetric C 12 + Pt 198 systems

Hindrance at deep subbarrier energies for the symmetric $^{58}\mathrm{Ni}+^{58}\mathrm{Ni}, ^{64}\mathrm{Ni}+^{64}\mathrm{Ni}$, and asymmetric $^{12}\mathrm{C}+^{198}\mathrm{Pt}$ systems is investigated using microscopic energy and the density-dependent $G$-matrix effective interaction. The proton and neutron density distributions of target and projectile are derived from Skyrme-Hartree-Fock calculations. A fair agreement with the data of the fusion excitation functions and astrophysical $S$ factors have been obtained without any fitting parameters. Hindrance is naturally reproduced at deep subbarrier energies, which is consistent with experimental observations.