Nuclear viscosity estimated by dynamics of neck formation in the early stage of nuclear collision

TL;DR

This paper estimates nuclear viscosity by simulating the early stage of nuclear collision neck formation using a Langevin equation approach, revealing a transition from viscous to inertial coalescence similar to macroscopic drops.

Contribution

It introduces a novel method to estimate nuclear viscosity through dynamic simulation of neck formation in nuclear collisions.

Findings

Identifies a viscous to inertial transition in nuclear neck growth.

Estimates nuclear viscosity coefficient using hydrodynamical analogy.

Demonstrates the applicability of macroscopic drop models to nuclear matter.

Abstract

The very early stage of the coalescence of two nuclei is studied and used to estimate the nuclear viscosity. The time evolution of the neck region has been simulated by the unified Langevin equation method, which is used in the analysis of heavy-ion collisions from the approaching stage to the fusion-fission stage. It is found that the transition from viscous to inertial coalescence that appeared in the neck growth of macroscopic drops can also be seen in the present simulation in nucleus-nucleus collisions. The dynamics of neck growth is analyzed in terms of the hydrodynamical formula and the viscosity coefficient of nuclear matter is estimated using the analogy of macroscopic drops.