Isospin effects and the density dependence of the nuclear symmetry energy

TL;DR

This study examines how the nuclear symmetry energy's density dependence influences fragment distributions in nuclear reactions, using a statistical model with Skyrme interactions, highlighting the sensitivity of isotopic distributions to the force parameters.

Contribution

It introduces a comprehensive analysis of the symmetry energy's density dependence using the Statistical Multifragmentation Model with various Skyrme forces, considering finite temperature effects.

Findings

Isoscaling analysis is insensitive to different Skyrme forces.

Isotopic distributions are highly sensitive to the choice of Skyrme force.

Thermal dilation affects fragment observables but does not distinguish force models.

Abstract

The density dependence of the nuclear symmetry energy is inspected using the Statistical Multifragmentation Model with Skyrme effective interactions. The model consistently considers the expansion of the fragments' volumes at finite temperature at the freeze-out stage. By selecting parameterizations of the Skyrme force that lead to very different equations of state for the symmetry energy, we investigate the sensitivity of different observables to the properties of the effective forces. Our results suggest that, in spite of being sensitive to the thermal dilation of the fragments' volumes, it is difficult to distinguish among the Skyrme forces from the isoscaling analysis. On the other hand, the isotopic distribution of the emitted fragments turns out to be very sensitive to the force employed in the calculation.