Nuclear stopping for heavy-ion induced reactions in the Fermi Energy range : from 1-Body to 2-Body dissipation

TL;DR

This paper investigates how nuclear stopping in heavy-ion reactions varies around the Fermi energy, highlighting a transition from mean-field to nucleon-nucleon collision regimes and extracting relevant nuclear matter properties.

Contribution

It provides experimental evidence for the change in dissipation mechanisms and offers comprehensive estimates of nucleon mean free path and cross sections at Fermi energies.

Findings

Minimal stopping occurs around the Fermi energy.

Transition from 1-body to 2-body dissipation regimes.

Extracted nucleon mean free path and cross section values.

Abstract

We address the stopping in heavy-ion induced reactions around the Fermi energy using central collisions recorded with \emph{INDRA} $4\pi$ array. The stopping is minimal around the Fermi energy and corresponds to the disappearance of the Mean-Field effects and the appearance of nucleon-nucleon elastic collisions. This phenomenon is attributed to a change in the dissipation regime going from 1-body (Mean-Field) dissipation at low incident energy to 2- body (nucleonic collisions) above the Fermi energy. A connection to the in-medium transport properties of nuclear matter is proposed and comprehensive values of the nucleon mean free path $\lambda_{NN}$ and the nucleon-nucleon cross section are extracted.