Dispersion of longitudinal momentum distributions induced in fragmentation reactions

TL;DR

This paper analyzes the momentum distribution fluctuations in nuclear fragmentation reactions across the entire production range, introducing a new analytical formula that incorporates various reaction mechanisms for improved description.

Contribution

It extends previous studies to include all fragment types and derives a new analytical formula for the variance of momentum distributions considering multiple reaction processes.

Findings

Extended the analysis to all fragment types including lightest fragments

Developed a new analytical formula for momentum distribution variance

Incorporated effects of abrasion, evaporation, and thermal break-up

Abstract

On the basis of systematic measurements of fragmentation reactions, which provide a detailed overview on the velocity distributions of residual nuclei, an improved description of the kinematical properties of the fragmentation residues is established. This work is dedicated to the fluctuations of their momentum distributions. In contrast to previous investigations, limited to close-to-projectile fragments, we extended our study to the entire production range, down to the lightest observed fragments. In this context, beside the contribution of abrasion and evaporation processes, we considered the effect of the thermal break-up on the width of the momentum distributions. Using approximated theoretical descriptions of the different reaction stages, a new analytical formula for the variance of the momentum distribution is derived, which is well adapted to technical applications.