Derivative corrections to the symmetry energy and the isovector   dipole-resonance structure in nuclei
  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. 
J.P. Blocki, A.G. Magner, and P. Ring
nucl-th