Seminar des IAS-4/IKP-3
Inclusive breakup of 209Bi(6Li, αX) and related topics
Tongji University, Shanghai, China
In this talk, I will discuss the inclusive breakup reaction of 209Bi(6Li, alpha X). For that, the Ichimura-Austern-Vincent model proposed in the 1980s iis applied and compared with the experimental data. In addition, I will also discuss the suppression of complete fusion of 6Li with respect to the expectation for tightly bound nuclei at energies above the Coulomb barrier. Although it is widely accepted that the phenomenon is related to the weak binding of these nuclei, the origin of this suppression is not fully understood. Here, we present a novel approach that provides the complete fusion for weakly bound nuclei and relates its suppression to the competition between the different mechanisms contributing to the reaction cross section. The method is applied to the 6Li+209Bi reactions, where we find that the suppression of complete fusion is mostly caused by the flux associated with nonelastic breakup modes, such as the partial capture of the projectile (incomplete fusion), whereas the elastic breakup mode is found to play a minor role. On the other hand, the incomplete fusion has been commonly assumed to be a two-step process, whose first step is the dissociation of the weakly bound nucleus, followed by the capture of one of the fragments, To assess this interpretation, we applied the three-body model of inclusive breakup model proposed in the 1980s by Austern et al., that accounts for both the direct, one-step, partial fusion and the two-step mechanism proceeding via the projectile continuum states. Contrary to the widely assumed picture, we find that, at least for the investigated cases, the partial fusion is largely dominated by the direct capture from the projectile ground state.