Residual proton-neutron interactions and the $N_{\rm p} N_{\rm n}$ scheme

TL;DR

This paper explores the relationship between proton-neutron interactions and the $N_{p}N_{n}$ scheme, confirming a nearly linear correlation that supports its applicability to nuclei far from stability.

Contribution

The study refines a formula for integrated proton-neutron interactions and demonstrates a strong linear correlation with the $N_{p}N_{n}$ scheme using recent experimental data.

Findings

Nearly linear correlation between proton-neutron interactions and $N_{p}N_{n}$.

Validation of the $N_{p}N_{n}$ scheme for nuclei far from stability.

Improved formula for integrated proton-neutron interactions.

Abstract

We investigate the correlation between integrated proton-neutron interactions obtained by using the up-to-date experimental data of binding energies and the $N_{\rm p} N_{\rm n}$, the product of valence proton number and valence neutron number with respect to the nearest doubly closed nucleus. We make corrections on a previously suggested formula for the integrated proton-neutron interaction. Our results demonstrate a nice, nearly linear, correlation between the integrated p-n interaction and $N_{\rm p} N_{\rm n}$, which provides us with a firm foundation of the applicability of the $N_{\rm p} N_{\rm n}$ scheme to nuclei far from the stability line.