Semiclassical description of the isovector giant dipole resonance

The isovector dipole excitations in spherical nuclei are considered within a kinetic-theory approach, which explicitly exploits the effective nuclear surface as a collective variable. It is shown that the surface symmetry potential plays an essential role in the structure of the giant dipole resonance. It is found, that the obtained strength distribution is in the agreement with the experimental one, when both volume and surface interactions are included simultaneously.