Determination of the nucleon-nucleon interaction in the ImQMD model by nuclear reaction at the Fermi energy region

TL;DR

This study uses the ImQMD model to analyze how different parameter sets affect nucleon-nucleon interactions in nuclear reactions at Fermi energies, identifying optimal parameters and key observables.

Contribution

It demonstrates that charge distribution and fragment multiplicity are effective for studying N-N interactions and identifies IQ3 as the best parameter set for the ImQMD model.

Findings

Charge distribution is sensitive below the multifragmentation threshold.

IQ3 reproduces experimental fragment spectra accurately.

Fermi energy region is ideal for probing N-N interactions.

Abstract

The nucleon-nucleon interaction is investigated by using the ImQMD model with the three sets of parameters IQ1, IQ2 and IQ3 in which the corresponding incompressibility coefficients of nuclear matter are different. The charge distribution of fragments for various reaction systems are calculated at different incident energies. The parameters strongly affect the charge distribution below the threshold energy of nuclear multifragmentation. The fragment multiplicity spectrum for $^{238}$U+$^{197}$Au at 15 AMeV and the charge distribution for $^{129}$Xe+$^{120}$Sn at 32 and 45 AMeV, and $^{197}$Au+$^{197}$Au at 35 AMeV are reproduced by the ImQMD model with the set of parameter IQ3. It is concluded that charge distribution of the fragments and the fragment multiplicity spectrum are good observables for studying N-N interaction, the Fermi energy region is a sensitive energy region to explore the N-N interaction, and IQ3 is a suitable set of parameters for the ImQMD model.