Medium effect in high-density nuclear matter probed by a systematic analysis of nucleus-nucleus elastic scattering

We investigate the property of the high-density nuclear matter probed by the nucleus-nucleus elastic scattering in the framework of the double-folding model with the complex $G$-matrix interaction. The medium effect including the three-body-force (TBF) effect is investigated with present two methods based on the frozen density approximation. The medium effect is clearly seen on the potential and the elastic cross section for the $^{16}\mathrm{O}+\phantom{\rule{0.16em}{0ex}}^{16}\mathrm{O}$ system at $E/A=70\phantom{\rule{4pt}{0ex}}\mathrm{MeV}$. The crucial role of the medium effect is also confirmed with other effective nucleon-nucleon ($\mathit{NN}$) interactions. In addition, the present methods are applied to other heavy-ion elastic scattering systems. Again, the medium effect is clearly seen in the heavy-ion elastic cross section. The medium effect on the elastic cross section becomes invisible with the increase of the target mass and the incident energy (up to $E/A=200\phantom{\rule{4pt}{0ex}}\mathrm{MeV}$). However, the medium effect is again important to fix the heavy-ion scattering over $E/A=200\phantom{\rule{4pt}{0ex}}\mathrm{MeV}$. Finally, we make clear the crucial role of the TBF effect up to ${k}_{F}=1.6\phantom{\rule{4pt}{0ex}}{\mathrm{fm}}^{\ensuremath{-}1}$ in the nucleus-nucleus elastic scattering.