Random-phase-approximation-based dynamical polarization potential

Abstract

A dynamical polarization potential is defined taking into account the effects on the elastic channel due to the excitation of vibrational collective modes, described within the random-phase approximation. The probability amplitudes for exciting these modes are evaluated by integration along classical trajectories determined by the real part of the nucleus-nucleus potential with energy and angular momentum loss. Calculations performed for the 40Ca+40Ca system show that, at high bombarding energy (E/A=44 MeV), both the real and the imaginary parts of the polarization potential arise mainly from the excitation of the high-lying modes. At energies near the Coulomb barrier, the calculated elastic cross section is in good agreement with the experimental data. The inclusion of the real part of the polarization potential improves this agreement.