Break-up fragment topology in statistical multifragmentation models

TL;DR

This paper investigates fragmentation patterns and energy fluctuations in a microcanonical model, revealing a bubble-like freeze-out volume and how fragment localization relates to kinematic properties, with implications for experimental inference.

Contribution

It introduces a detailed analysis of fragment topology and energy fluctuations in statistical multifragmentation models, highlighting the bubble-like structure of the freeze-out volume.

Findings

Energy fluctuations are insensitive to freeze-out volume constraints.

The freeze-out volume exhibits a bubble-like structure due to hard-core repulsion.

Largest fragment localization can be inferred from their kinematic properties.

Abstract

Break-up fragmentation patterns together with kinetic and configurational energy fluctuations are investigated in the framework of a microcanonical model with fragment degrees of freedom over a broad excitation energy range. As far as fragment partitioning is approximately preserved, energy fluctuations are found to be rather insensitive to both the way in which the freeze-out volume is constrained and the trajectory followed by the system in the excitation energy - freeze-out volume space. Due to hard-core repulsion, the freeze-out volume is found to be populated un-uniformly, its highly depleted core giving the source a bubble-like structure. The most probable localization of the largest fragments in the freeze-out volume may be inferred experimentally from their kinematic properties, largely dictated by Coulomb repulsion.