Versions of the M3Y effective nucleon-nucleon interaction, with different prescriptions for the knock-on exchange contributions and density dependence, have been used in a study of the energy dependence of the nucleon optical potential in nuclear matter as well as in a systematic folding model analysis of the elastic ${}_{}{}^6{}_{}{}^{}\mathrm{Li}$${+}^{12}$C scattering data at ${\mathit{E}}_{\mathrm{lab}}$=60–318 MeV to study the energy dependence of the ${}_{}{}^6{}_{}{}^{}\mathrm{Li}$${+}^{12}$C optical potential. Contributions from the (breakup) dynamical polarization potential to the real part of the ${}_{}{}^6{}_{}{}^{}\mathrm{Li}$${+}^{12}$C optical potential are simulated by a surface correction using splines added to the real folded potential. This is shown to be strongest at ${\mathit{E}}_{\mathrm{lab}}$=99 MeV. The correction needed to fit the data is found to be qualitatively similar to that predicted theoretically for breakup of the ${}_{}{}^6{}_{}{}^{}\mathrm{Li}$. The optical model analysis of the refractive ${}_{}{}^6{}_{}{}^{}\mathrm{Li}$${+}^{12}$C scattering data, using different types of real folded potential, shows that the most successful is the folded potential built upon density-dependent interactions, which have parameters chosen to reproduce the saturation properties of nuclear matter and which predict a nuclear incompressibility K around 200 MeV.

• Received 1 December 1994

DOI:https://doi.org/10.1103/PhysRevC.51.2069