Behavior of ${}^6$Li + ${}^{144}$Sm elastic and inelastic angular distributions in the region of the Coulomb barrier

Elastic and inelastic scattering angular distributions (ADs) for the ${}^6$Li + ${}^{144}$Sm system in the 21-45 MeV energy range are analyzed with a Woods-Saxon phenomenological and two microscopic optical potentials, with one derived from the São Paulo formulation and the other from cluster folding of realistic alpha and deuteron potentials. Energy-dependent real, J${}_V$, and imaginary, J${}_W$, potential volume integrals are extracted from each potential system. It is shown that their variation in the region of the Coulomb barrier displays the normal threshold anomaly of strong coupling between the real and imaginary potentials. The reduced energy dependence on the extracted reduced reaction cross sections for the ${}^6$Li + ${}^{144}$Sm system is presented and compared to the calculated one using Wong's formula. The strength and energy dependence of the inelastic ADs are reasonably described using the adopted potentials within the framework of the coupled channels method.