Exotic break-up modes in heavy ion reactions at low energies

TL;DR

This paper investigates new dynamical ternary breakup mechanisms in low-energy heavy ion collisions, revealing how surface instabilities and angular momentum lead to a precursor of neck emission, with implications for understanding nuclear symmetry energy.

Contribution

It introduces a novel analysis of ternary breakup modes in heavy ion reactions at low energies using the Stochastic Mean Field model, highlighting their dynamical origin and connection to neck emission.

Findings

Identification of dynamical ternary breakup events in semi-central collisions.

Demonstration of the role of surface instabilities and angular momentum in fragmentation.

Potential to explore nuclear symmetry energy in neutron-rich systems.

Abstract

New reaction mechanisms occurring in heavy ion collisions at low energy (10- 30 MeV/A) are investigated within the Stochastic Mean Field model. We concentrate on the analysis of ternary breakup events, of dynamical origin, occurring in semi-central reactions, where the formation of excited systems in various conditions of shape and angular momentum is observed. We show how this fragmentation mode, which can be considered as a precursor of the neck emission observed at higher beam energies, emerges from the combined action of surface (neck) instabilities and angular momentum effects. Interesting perspectives are opening towards the investigation of this mechanism in neutron-rich (or exotic) systems, with the possibility to access information on the low-density behavior of the nuclear symmetry energy.