Reexamining the "finite-size" effects in isobaric yield ratios using a statistical abrasion-ablation model

TL;DR

This paper investigates the finite-size effects in isobaric yield ratios using a modified statistical abrasion-ablation model, revealing that these effects diminish with neutron-rich projectiles, challenging previous ensemble-based conclusions.

Contribution

It introduces a modified SAA model to reexamine finite-size effects in IYR, providing new insights that differ from traditional statistical ensemble predictions.

Findings

Finite-size effects depend on projectile isospin and size.

Neutron-rich projectiles weaken or eliminate finite-size effects.

Results challenge the validity of grand-canonical and canonical models for neutron-rich reactions.

Abstract

The "finite-size" effects in the isobaric yield ratio (IYR), which are shown in the standard grand-canonical and canonical statistical ensembles (SGC/CSE) method, is claimed to prevent obtaining the actual values of physical parameters. The conclusion of SGC/CSE maybe questionable for neutron-rich nucleus induced reaction. To investigate whether the IYR has "finite-size" effects, the IYR for the mirror nuclei [IYR(m)] are reexamined using a modified statistical abrasion-ablation (SAA) model. It is found when the projectile is not so neutron-rich, the IYR(m) depends on the isospin of projectile, but the size dependence can not be excluded. In reactions induced by the very neutron-rich projectiles, contrary results to those of the SGC/CSE models are obtained, i.e., the dependence of the IYR(m) on the size and the isospin of the projectile is weakened and disappears both in the SAA and the experimental results.