Effects of the difference of deformations of the neutron and proton distributions on heavy ion fusion reactions

Fusion reactions in heavy ion collisions at energies below the Coulomb barrier take place through quantum tunneling. For low to medium mass stable nuclei, the experimental data of the fusion cross section and the so called fusion barrier distribution are known to be well reproduced by coupled-channels calculations which take nuclear intrinsic degrees of freedom, such as rotational and/or surface vibrational excitations of the colliding nuclei, into account. In this seminar, I discuss the novel effects which appear in the fusion cross section in the case, where the projectile has different deformations for the proton and neutron density distributions. This situation could happen when an exotic neutron rich or proton rich nucleus is used as the projectile. (author)