Fragmentation paths in dynamical models

TL;DR

This paper compares two dynamical models, AMD and SMF, for nuclear fragmentation reactions, analyzing how their different mechanisms affect fragment properties and implications for symmetry energy studies.

Contribution

It provides a quantitative comparison of AMD and SMF models, highlighting differences in fragmentation mechanisms and their impact on reaction observables and isospin content.

Findings

Reaction paths differ significantly between models.

Fragment isotopic properties depend on the model used.

Implications for symmetry energy extraction from collision data.

Abstract

We undertake a quantitative comparison of multi-fragmentation reactions, as modeled by two different approaches: the Antisymmetrized Molecular Dynamics (AMD) and the momentum-dependent stochastic mean-field (SMF) model. Fragment observables and pre-equilibrium (nucleon and light cluster) emission are analyzed, in connection to the underlying compression-expansion dynamics in each model. Considering reactions between neutron-rich systems, observables related to the isotopic properties of emitted particles and fragments are also discussed, as a function of the parametrization employed for the isovector part of the nuclear interaction. We find that the reaction path, particularly the mechanism of fragmentation, is different in the two models and reflects on some properties of the reaction products, including their isospin content. This should be taken into account in the study of the density dependence of the symmetry energy from such collisions.