Dipole polarizability in deuteron scattering around the Coulomb barrier

The effect of dipole polarizability in the scattering of deuterons by Pb-20 8 at energies around the Coulomb barrier is studied, using dynamic polariza tion potentials. At energies well below the barrier, we find that the dynam ic polarization potential, which is complex and energy-dependent in general , can be approximated by the adiabatic expression, while the nuclear potent ial is negligible. At energies around and above the Coulomb barrier, the in clusion of the dynamic polarization potential along with the nuclear potent ial allows for a better fit of the elastic cross sections. The nuclear pote ntials obtained from the fit have reasonable values of the diffuseness para meters and their energy dependence is consistent with dispersion relations. (C) 1999 Elsevier Science B.V.