Interaction of the single-particle and collective degrees of freedom in non-magic nuclei: the role of phonon tadpole terms

TL;DR

This paper develops a method to incorporate phonon contributions, including tadpole terms, into the analysis of non-magic nuclei, improving understanding of single-particle properties and pairing phenomena.

Contribution

It introduces a consistent approach to account for phonon tadpole terms in mass and gap operators without additional parameters.

Findings

Phonon tadpoles significantly affect single-particle energies.

The method clarifies the role of surface pairing in nuclei.

Results enhance the understanding of collective and single-particle interactions.

Abstract

A method of a consistent consideration of the phonon contributions to mass and gap operators in non-magic nuclei is developed in the so-called g^2 approximation, where g is the low-lying phonon creation amplitude. It includes simultaneous accounting for both the usual non-local terms and the phonon tadpole ones. The relations which allow the tadpoles to be calculated without any new parameters are derived. As an application of the results, the role of the phonon tadpoles in the single-particle strength distribution and in the single-particle energies and gap values has been considered. Relation to the problem of the surface nature of pairing is discussed.