# Fusion process studied with preequilibrium giant dipole resonance in time dependent Hartree-Fock theory

## TL;DR

This study uses Time-Dependent Hartree-Fock theory to analyze the pre-equilibrium Giant Dipole Resonance during heavy nuclei fusion, revealing new insights into the fusion process and potential pathways for synthesizing super heavy elements.

## Contribution

It demonstrates the excitation of pre-equilibrium GDR in asymmetric fusion and links its characteristics to the structure of the fused system, providing new understanding of fusion dynamics.

## Key findings

- Lowered pre-equilibrium GDR energy compared to statistical predictions
- Evidence of GDR energy lowering from experimental data
- Enhanced gamma-ray emission suggests a cooling mechanism during fusion

## Abstract

The equilibration of macroscopic degrees of freedom during the fusion of heavy nuclei, like the charge and the shape, are studied in the Time-Dependent Hartree-Fock theory. The pre-equilibrium Giant Dipole Resonance (GDR) is used to probe the fusion path. It is shown that such isovector collective state is excited in N/Z asymmetric fusion and to a less extent in mass asymmetric systems. The characteristics of this GDR are governed by the structure of the fused system in its preequilibrium phase, like its deformation, rotation and vibration. In particular, we show that a lowering of the pre-equilibrium GDR energy is expected as compared to the statistical one. Revisiting experimental data, we extract an evidence of this lowering for the first time. We also quantify the fusion-evaporation enhancement due to gamma-ray emission from the pre-equilibrium GDR. This cooling mechanism along the fusion path may be suitable to synthesize in the future super heavy elements using radioactive beams with strong N/Z asymmetries in the entrance channel.