Isoscaling constraining sources' sizes

TL;DR

This paper extends nuclear isoscaling analysis within the Statistical Multifragmentation Model to constrain the ratio of source sizes in heavy-ion collisions, demonstrating a robust scaling law sensitive to source size and resilient to finite size and deexcitation effects.

Contribution

The study introduces a novel application of isoscaling to determine source size ratios, supported by analytical and simulation evidence within the grand-canonical ensemble framework.

Findings

Scaling law for fragment probabilities depends on source size ratio

Scaling law remains robust against finite size and deexcitation effects

Poisson distribution approximates fragment probability distributions well

Abstract

In the framework of the Statistical Multifragmentation Model, the nuclear isoscaling analysis is extended to constrain the ratio between the sizes of the decaying sources formed in a collision between two heavy ions. It is found that the ratio between the probabilities of observing n fragments in each event, for each of the sources, follows a scaling law, similar to the traditional nuclear isoscaling. However, the corresponding slope is also sensitive to the sources' sizes. This property is explained analytically using the grand-canonical ensemble. The extent to which our findings are affected by finite size effects and by the deexcitation of the hot primary fragments is also investigated. The scaling turns out to be robust and weakly affected by effects implied by these two aspects. We also find that the Poisson distribution is a fairly good approximation to the above mentioned probabilities, associated with both the primordial fragments, produced at the breakup stage, and the final ones, found at the end of the fragment deexcitation process.