Probing nuclear structure and the equation of state through pre-equilibrium dipole emission in charge-asymmetric reactions

TL;DR

This study explores how pre-equilibrium dipole emission in charge-asymmetric heavy-ion reactions reveals insights into nuclear structure and the nuclear equation of state, using advanced theoretical models to analyze experimental data.

Contribution

It provides a comparative analysis of different theoretical approaches to disentangle deformation effects and quantal structure influences on dipole emission in heavy-ion collisions.

Findings

Deformation effects significantly influence dipole emission.

Residual two-body collisions impact reaction dynamics.

Insights into the nuclear equation of state from emission patterns.

Abstract

We investigate the pre-equilibrium dipole response in the charge-asymmetric reaction $^{40}$Ca+$^{152}$Sm, of recent experimental interest, at several beam energies within the range $[5, 11]$ AMeV and different collision centralities. By employing Skyrme-like effective interactions for the nuclear mean field, we probe the role of the different ingredients performing theoretical calculations based on the time-dependent Hartree-Fock approach or a semi-classical transport model that also includes two-body correlations. A comparative analysis between these approaches allowed us to disentangle the role of deformation effects in the entrance channel from the ones associated with structure details of genuine quantal nature on the dipole emission. Moreover, we also investigate the impact of the occurrence of residual two-body collisions on the reaction dynamics. This study contributes to the understanding of the microscopic processes that determine the complex dynamics of low-energy heavy-ion collisions along the fusion-fission path, which is relevant to super-heavy element synthesis, unraveling interesting connections with the characteristics of the nuclear effective interaction and the associated equation of state.