Unified Description of Nuclear Stopping in Central Heavy-ion Collision from 10$A$ MeV to 1.2$A$ GeV

TL;DR

This paper analyzes nuclear stopping in central heavy-ion collisions across a wide energy range using a transport model, revealing energy-dependent trends in equilibration and fragment penetration, and comparing results with experimental data.

Contribution

It provides a comprehensive analysis of nuclear stopping from 10A MeV to 1.2A GeV using IQMD, highlighting energy-dependent behaviors and the role of fragment hierarchy.

Findings

Mean isotropy reaches a minimum near Fermi energy.

Equilibration is not achieved even in central collisions.

Heavy fragments tend to penetrate more, constraining nuclear equation of state.

Abstract

The detailed analysis of wide excitation function of nuclear stopping has been studied within a transport model, Isospin-dependent Quantum Molecular Dynamics model (IQMD) and an overall good agreement with the INDRA and FOPI experimental data has been achieved. It is found that mean value of isotropy in central Heavy-Ion Collision (HIC) reaches a minimum near Fermi energy and approaches a maximum around 300 - 400$A$ MeV. This suggests that, in statistical average, the equilibration is far from being reached even in central HIC especially near Fermi energy. A hierarchy in stopping of fragments, which favors heavy fragments to penetrate, provides a robust restriction on the global trend of nuclear stopping and could serve as a probe for nuclear equation of state.