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

TL;DR

This study systematically analyzes how medium effects, including three-body forces, influence nucleus-nucleus elastic scattering, revealing their significance at specific energies and target masses in high-density nuclear matter.

Contribution

It introduces two methods based on the frozen density approximation to investigate medium effects, including three-body-force effects, on elastic scattering in high-density nuclear matter.

Findings

Medium effects significantly impact elastic scattering potentials and cross sections at 70 MeV/nucleon.

The medium effect diminishes with increasing target mass and energy but remains important above 200 MeV/nucleon.

Three-body-force effects are crucial up to a Fermi momentum of 1.6 fm$^{-1}$ in elastic scattering analyses.

Abstract

We investigate the property of the high-density nuclear matter probed by the nucleus-nucleus elastic scattering in the framework of the double-folding (DF) model with the complex $G$-matrix interaction. The medium effect including three-body-force (TBF) effect is investigated with present two methods based on the frozen density approximation (FDA). The medium effect is clearly seen on the potential and the elastic cross section for the $^{16}$O + $^{16}$O system at $E/A =$ 70 MeV. The crucial role of the medium effect is also confirmed with other effective nucleon-nucleon ($NN$) 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 MeV). However, the medium effect is again important to fix the heavy-ion scattering over $E/A =$ 200 MeV. Finally, we make clear the crucial role of the TBF effect up to $k_F =$ 1.6 fm$^{-1}$ in the nucleus-nucleus elastic scattering.