# Iso-vector dipole resonance and shear viscosity in low energy heavy-ion collision

## TL;DR

This paper investigates the relationship between the iso-vector dipole resonance and shear viscosity in low energy heavy-ion collisions, revealing a quantum effect linking IVGDR peak energy to viscosity over entropy density.

## Contribution

It introduces a combined analysis of IVGDR and shear viscosity using the Green-Kubo method within a quantum molecular dynamics framework, highlighting a novel quantum correlation.

## Key findings

- IVGDR peak energy correlates positively with shear viscosity over entropy density.
- The study demonstrates a quantum effect distinguishing nuclear matter from classical fluids.
- Transport properties are extracted after the system reaches local equilibrium.

## Abstract

The ratio of shear viscosity over entropy density in low energy heavy-ion collision has been calculated by using the Green-Kubo method in the framework of an extended quantum molecular dynamics model. After the system almost reaching a local equilibration for a head-on $^{40}$Ca+$^{100}$Mo collision, thermodynamic and transport properties are extracted. Meanwhile, iso-vector giant dipole resonance (IVGDR) of the collision system is also studied. By the Gaussian fits to the IVGDR photon spectra, the peak energies of IVGDR are extracted at different incident energies. The result shows that the IVGDR peak energy has a positive correlation with the ratio of shear viscosity over entropy density. This is a quantum effect and indicates a difference between nuclear matter and classical fluid.