Effect of resonance states of the weakly bound 6Li on total fusion in reactions with targets 28Si, 96Zr and 209Bi

Abstract

Continuum Discretized Coupled-Channel calculations of total fusion cross sections for reactions induced by the weakly bound nucleus 6Li with targets 28Si, 96Zr and 209Bi at energies around the Coulomb barrier are presented. In the cluster structure frame of 6Li → α+d, short-range absorption potentials are considered for the interactions between the α- and d-fragments with the targets. In the model, the effect of resonance (l = 2, Jπ = 3+, 2+, 1+) and non-resonance breakup states of 6Li on fusion is studied by using two approaches: (1) by omitting the resonance states from the full discretized CDCC breakup space and 2) by considering only the resonance discretized sub-space. Among other things, it is found that resonance breakup states produce strong repulsive polarization potentials that lead to fusion suppression. The particular effect on fusion of a single resonance is calculated. It is found that resonances 2+ and 1+ have a more significant role on incomplete fusion, while the 3+ on complete fusion.