Microscopic evaluation of the pairing gap

TL;DR

This paper reviews recent progress and ongoing challenges in the microscopic theory of nuclear pairing correlations, comparing finite nuclei with nuclear matter and highlighting unresolved issues in many-body effects.

Contribution

It provides a comprehensive overview of current theoretical approaches, discrepancies among calculations, and identifies open problems in understanding nuclear pairing mechanisms.

Findings

Comparison of different models shows partial agreement and remaining discrepancies.

The role of many-body correlations like screening is still uncertain.

Further investigation is needed into effects beyond the BCS scheme.

Abstract

We discuss the relevant progress that has been made in the last few years on the microscopic theory of the pairing correlation in nuclei and the open problems that still must be solved in order to reach a satisfactory description and understanding of the nuclear pairing. The similarities and differences with the nuclear matter case are emphasized and described by few illustrative examples. The comparison of calculations of different groups on the same set of nuclei show, besides agreements, also discrepancies that remain to be clarified. The role of the many-body correlations, like screening, that go beyond the BCS scheme, is still uncertain and requires further investigation.