Fusion and decay dynamics of 6 Li + 120Sn and 7 Li + 119Sn reactions across the Coulomb barrier

Abstract

In reference to the complete fusion (CF) and incomplete fusion (ICF) processes, the analysis of 6 Li + 120Sn and 7 Li + 119Sn reactions forming the 126I compound nucleus (CN) is carried out at incident energies spreading across the Coulomb barrier. The theoretical calculations of the formation of the compound nucleus 126I via two different entrance channels are done by opting for the energy-dependent Woods-Saxon potential (EDWSP) model and the -summed Wong model. The available CF cross-section data of these systems at above-barrier energies is suppressed with respect to the EDWSP outcomes, and a reducing factor is needed to explain above-barrier CF data of given reactions. Such suppression effects at above-barrier energies can be correlated with the breakup of weakly bound systems (6,7 Li) before reaching the Coulomb barrier. The total fusion (TF) cross-section data, which are the sum of CF and ICF cross-section data, are fairly addressed by using the EDWSP predictions. The difference between CF and TF data represents ICF yields and hence qualified in terms of range parameter r0. Besides this, the -summed Wong approach has been used to address CF, ICF, and TF cross-section data, which limits the contribution of partial waves to the maximum value. Within the -summed Wong model, the CF and ICF contributions are separated out on the basis of the angular-momentum window. In the angular-momentum distribution case, CF and ICF contributions are estimated in view of -windows assigned for CF ( = 0 to crit.) and ICF (crit. to max) components. Furthermore, the decay analysis of 126I compound nucleus is made using the dynamical cluster decay model (DCM). Calculations are made to analyze the decay cross sections σxn of neutron channels for given entrance channels at a wide spread of energies (Elab = 14–28 MeV). The neck-length parameter R, which decides the first turning point, is optimized to address the decay cross sections of different neutron evaporation channels and DCM-based calculations fairly explained the decay patterns of the CN.