Roles of multi-step transfer in fusion process induced by heavy-ion reactions

摘要

In nucleus-nucleus collisions of the systems, (sup 12)C+(sup 13)C and (sup 13)C+(sup 16)O-(sup 12)C+(sup 17)O, the effects of the multi-step transfers and inelastic excitations on the fusion cross sections are investigated in the framework of the coupled-reaction-channel (CRC) method. Strong CRC effects of the multi-step processes are observed. Namely, the valence neutron in (sup 13)C or (sup 17)O plays an important role in the enhancement of the fusion. The potential barrier is effectively lowered with the formation of the covalent molecule of the configuration, (sup 12)C+n+(sup 12)C or (sup 12)C+n+(sup 16)O. In the analyses of the system (sup 12)C+(sup 13)C, however, it is still required to introduce core-core optical potential of lower barrier height in the state of the positive total parity. This could be due to the neck formation with the nucleons contained in two core nuclei. (author). (ERA citation 19:005755)