Role of Resonances in Total, Coulomb, and Nuclear Breakup Cross Sections for Light and Heavy Targets

Abstract The influence of resonances on the breakup dynamics of the $${^6}$$ Li+ $$^{58}$$ Ni and $${^6}$$ Li+ $$^{208}$$ Pb systems is investigated using the continuum discretized coupled-channels (CDCC) method at incident energies above the Coulomb barrier. The calculated elastic scattering angular distributions are found to reproduce the available experimental data for both systems. The effects of resonances on the total, Coulomb, and nuclear breakup cross sections are analyzed as functions of scattering angle and incident energy. For the $${^6}$$ Li+ $$^{58}$$ Ni system, non-resonant breakup contributions dominate the nuclear and total breakup cross sections, while resonance effects remain relatively weak. In contrast, resonant breakup cross section plays a significant role in the $${^6}$$ Li+ $$^{208}$$ Pb reaction, particularly in the Coulomb breakup cross section. The results show that the influence of resonances decreases with increasing incident energy, indicating the growing importance of non-resonant continuum couplings at higher energies. The dependence of breakup observables on dipole, quadrupole, and octupole couplings is also investigated, revealing a pronounced sensitivity to the multipolarity of the coupling. These findings demonstrate that the importance of resonant and non-resonant breakup mechanisms depends strongly on the target mass and incident energy.