Coupled-Channel Analysis of Heavy Ion Fusion Reactions and Barrier Distributions

Heavy-ion fusion reactions in the proximity of the Coulomb barrier constitute a major focus of current experimental and theoretical research. Collisions within this energy domain proceed under the influence of multiple, well-distinguished reaction channels. In the near-barrier regime, the dynamical evolution of the system is predominantly governed by elastic scattering, various inelastic excitation modes, and the fusion of one or both interacting nuclei. The fusion mechanism is characterized by expressing the scattering potential as the contribution of both Coulomb and proximity potentials, and the process is interpreted within the framework of a one-dimensional barrier penetration model. In this study, conducted to understand heavy-ion fusion, the coupled-channel (CC) model was used. CC calculations allow for more accurate modeling of fusion probabilities, particularly below the barrier energy. This approach offers a richer description of the interactions that take place during the fusion process, helping to clarify theoretical expectations as well as experimental findings.Fusion cross sections for 30Si+ 26Mg, 32S+ 58Ni, 46,48,50Ti+ 124Sn,58Ni+ 58,64Ni, 64Ni+64Ni, 64,70Zn+ 64,70Zn heavy-ion systems were calculated using the CC model and a detailed analysis was performed. The calculations incorporated the lowest 2⁺ and 3⁻ excitation levels of both the projectile and target nuclei. The resulting theoretical predictions were subsequently evaluated against experimental observations as well as computations obtained from the NRV database. Overall, the analyses indicate that the applied CC model provides a highly accurate description of heavy-ion fusion dynamics.