First estimation of the fission dynamics of the spectator created in heavy-ion collisions

TL;DR

This paper presents the first dynamic investigation of fission and evaporation in spectator remnants from high-energy heavy-ion collisions, estimating their excitation energy and modeling their evolution with Langevin equations.

Contribution

It introduces a novel dynamical approach to study the de-excitation of spectators, combining excitation energy estimation with Langevin equation modeling.

Findings

Spectator excitation energy is around 100 MeV.

The model successfully describes fission and evaporation channels.

First dynamic analysis of spectator de-excitation in heavy-ion collisions.

Abstract

In peripheral high-energy heavy-ion collisions only parts of colliding nuclei interact leading to the production of a fireball. The remnants of such nuclei are called spectators. We estimated the excitation energy as a function of impact parameter. Their excitation energy is of the order of 100 MeV. The dynamical evolution of hot nuclei is described by solving a set of Langevin equations in four-dimensional collective coordinate space. The range of nuclear masses and excitation energies suits very well to ability of our model. Thus for the first time we investigate dynamically the fission and evaporation channels in de-excitation of the spectators produced in heavy-ions collision.