The extended Skyrme force versus realistic interactions: Application on 42Ca

The extended Skyrme force has been used to calculate self-consistently ground-state properties, pairing correlations and properties of excited states of spherical nuclei throughout the whole mass region. The shell-model matrix elements exhibit the same behaviour as the bare reaction matrix elements of realistic interactions, and to be renormalized due to core polarization effects (3p-1h, 4p-2h), to generate good effective interactions. A numerical application on ⁴²Ca is presented.