Microscopic description of the pygmy dipole resonance in neutron-rich Ca isotopes

We study the effects of the phonon-phonon coupling on the low-energy electric dipole response within a microscopic model based on an effective Skyrme interaction. The finite rank separable approach for the quasiparticle random phase approximation is used. Choosing as an example the isotopic chain of Calcium, we show the ability of the method to describe the low-energy E1 strength distribution. With one and the same set of parameters we describe available experimental data for 48Ca and predict the electric dipole strength function for 50Ca