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

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.