Nuclear excitation of Pygmy Dipole Resonance

Excitations of Pygmy Dipole Resonance (PDR), generated by a nuclear field, are studied within a semiclassical RPA based model. This is possible since the PDR, present in almost all nuclei with neutron excess, has a strong isoscalar character. Our results show that the employ of isoscalar probes finds its best use at incident energies below 50 MeV/u. The structural splitting of the low-lying E1 strength, found in recent (α,α'γ) experiments, is corroborated by our cross section calculations.