Derivative corrections to the symmetry energy and the isovector dipole-resonance structure in nuclei

TL;DR

This paper extends the effective surface approximation to include derivatives of the symmetry energy, enabling analytical calculations of isovector dipole resonance energies and sum rules that align well with experimental data.

Contribution

It introduces derivative corrections to the symmetry energy in the surface approximation, providing analytical insights into isovector dipole resonances.

Findings

Analytical expressions for isovector surface energy constants

Reasonable agreement with experimental resonance energies

Consistent sum rules with other models

Abstract

The effective surface approximation is extended accounting for derivatives of the symmetry energy density per particle. Using the analytical isovector surface energy constants within the Fermi-liquid droplet model, one obtains energies and sum rules of the isovector dipole resonance structure in a reasonable agreement with the experimental data and other theoretical approaches.