The effect of breakup of 6Li on elastic scattering and fusion with 28Si at near barrier energies

Elastic scattering angular distributions for Li-6+Si-28 system were measured at E-lab = 16, 21 MeV and analyzed along with the existing data from the previous measurements in the energy range of E-lab = 7.5 - 27 MeV. The measured cross-sections and the existing data, forming a set of angular distributions over a range of E/V-b = 0.9 - 3.23, were analyzed using the phenomenological optical model potential (OMP). Three different sets of potential parameters were used. The energy dependence of the real and the imaginary potential strengths were, subsequently, extracted at the radius of sensitivity (Rav) for the system. Continuum Discretized Coupled Channel (CDCC) calculation was performed to explore the contribution of projectile break-up (BU) on the observed energy dependence of the effective potential for elastic scattering of Li-6 from Si-28. The energy variation of the strength of the real potential with continuum coupling was found to agree with the energy dependence of the same extracted from the (OMP) analysis at energies around the barrier. But the behavior of the imaginary strength appeared to be different. The calculated fusion cross-sections, including the effect of BU, clearly overestimated the measured fusion excitation function data in the below and near barrier energies but compared well with the data at higher energies.