Isoscaling in statistical fragment emission in an extended compound nucleus model

TL;DR

This paper theoretically investigates isoscaling in nuclear fragment emission using an extended compound nucleus model, confirming experimental scaling laws and estimating the symmetry energy coefficient around 27 MeV.

Contribution

It introduces an extended model that predicts isoscaling behavior and accurately estimates the symmetry energy coefficient consistent with experimental data.

Findings

Isoscaling ratio follows exponential dependence on N and Z

Symmetry energy coefficient estimated at ~27 MeV

Surface entropy has minor impact on isoscaling behavior

Abstract

Based on an extended compound nucleus model, isospin effects in statistical fragment emission from excited nuclear systems are investigated. An experimentally observed scaling behavior of the ratio of isotope yields $Y_i(N,Z)$ from two similar emitting sources with different neutron-to-proton ratios is predicted theoretically, i.e., the relationship of $Y_2/Y_1 \propto exp(\alpha N + \beta Z)$ is demonstrated. The symmetry energy coefficient $C_{sym}$ extracted from the simulation results is $\sim$ 27 MeV which is consistent with realistic theoretical estimates and recent experimental data. The influence of the surface entropy on the isoscaling behavior is discussed in detail. It is found that although the surface entropy increases the numercial values of isoscaling parameters $\alpha$ and $\beta$, it does not affect the isoscaling behavior qualitatively and has only a minor effect on the extracted symmetry energy coefficient.