We analyzed experimental data on elastic $\alpha$ + $^{116}$Sn and $^{6}$Li + $^{116}$Sn scatterings at $E_{lab}=$ 240 MeV within the framework of the Coulomb-modified Glauber model. The ingredients of the model used in this work were the nucleon-nucleon ($NN)$ amplitude and the densities of the colliding nuclei. The calculations included the effective $NN $ amplitude considering a $q^{4}$ component and the surface-matched Gaussian density of the target nucleus. The calculated results reproduced satisfactorily the structures of differential cross sections and agreed well with the experimental data. \ The oscillatory structures observed in the angular distributions were explained using the strong interference between the near-side and the far-side scattering amplitudes. We found that the introduction of both an effective $NN$ amplitude and a surface-matched Gaussian density plays an important role in providing a better description of the elastic data.

Keywords: Coulomb-modified Glauber model, Effective $NN$ amplitude, Surface-matched Gaussian density, Elastic scattering, $\alpha$ + $^{116}$Sn, $^{6}$Li + $^{116}$Sn