Mechanism of breakup channel competition in the 6Li+209Bi system at above-barrier energies

The competition between the breakup channels in the 6 Li + 209 Bi fusion reaction at the above-barrier energies has been investigated using a classical dynamic model. By incorporating the breakup processes from the short-lived nucleus formed via direct excitation and n -stripping, the model provides a comprehensive description of both complete and incomplete fusion cross sections. Although the n -stripping channel exhibits a higher probability, it contributes less to the complete fusion cross section compared to the direct excitation channel. An unexpected behavior was observed in incomplete fusion at the above barrier energies: the light-fragment capture predominantly occurs near the critical angular momentum, while the α capture is favored at lower angular momenta, particularly in cases with large mass asymmetry between the two fragments. These findings provide further insight into the origin of fusion suppression in reactions involving weakly bound nuclei.