Quasiparticle Renormalization and Pairing Correlations in Spherical Superfluid Nuclei

Understand

We present a detailed discussion of the solution of Nambu-Gor'kov equations in superfluid nuclei, which provide a consistent framework to deal with the interplay between particle-hole and particle- particle channel, including the effects of the fragmentation of the quasiparticle strength and of the pairing interaction induced by the exchange of collective vibrations.

• The coupling between quasiparticle and vibrations is determined from the experimental polarizability of the low-lying collective surface vibrations.
• This coupling is used to renormalize the properties of quasiparticles obtained from a BCS calculation using the bare nucleon-nucleon interaction.
• We apply the formalism to the case of the nucleus 120Sn, showing results for the low-energy spectrum and the quasiparticle strength distribution in neighbouring odd nuclei and for the neutron pairing gap.