Theoretical Study of the Coupled-channel Effects in Fusion Reactions ^46,50Ti+¹²⁴Sn

The heavy-ion capture and fusion processes at energies near the Coulomb barrier can be treated as a multi-dimensional barrier penetration problem. In the eigenchannel framework, the couplings to other channels split the single potential barrier into a set of discrete barriers. Based on the concept of the barrier distribution, we have developed an empirical coupled-channel (ECC) model and performed a systematic study of capture excitation functions for 220 reaction systems. Recently, an experiment was reported in which the capture excitation functions of reactions ^46,50Ti+¹²⁴Sn were measured. In this work, we review the ECC model briefly and use this model together with the universal fusion function (UFF) prescription to study the coupled-channel effects in fusion reactions ^46,50Ti+¹²⁴Sn. The reduced fusion functions show that the sub-barrier capture cross sections of ⁴⁶Ti+¹²⁴Sn exhibit an extra enhancement as compared with those of ⁵⁰Ti+¹²⁴Sn. The results from the ECC model reproduce the experimental capture excitation functions successfully and show that this extra enhancement of the sub-barrier cross sections for ⁴⁶Ti+¹²⁴Sn can be ascribed to the positive Q value neutron transfer effect.