Correction to Relativistic Mean Field binding energy and $N_pN_n$ scheme

TL;DR

This paper investigates the discrepancies between experimental and Relativistic Mean Field binding energies across various nuclei, revealing that neutron-proton interactions primarily account for these differences, with a proportional relation to the Casten factor.

Contribution

It demonstrates that the neutron-proton interaction, measured by the Casten factor, explains the binding energy differences in a wide range of nuclei, extending previous understanding to odd-N nuclei.

Findings

Differences are proportional to the Casten factor P.

Neutron-proton interaction is the main contributor to binding energy discrepancies.

The relation holds for both even-even and even-Z odd-N nuclei.

Abstract

The differences between the experimental and Relativistic Mean Field binding energies have been calculated for a large number of even-even nuclei from A=50 to 220. Excluding certain mass regions, the differences, after suitable corrections for particular isotope chains, are found to be proportional to the Casten factor $P$, chosen as a measure of n-p interaction strength in a nucleus. Results for even-$Z$ odd-$N$ nuclei are also seen to follow the same relation, if the odd-even mass difference is taken into account following the semiempirical formula. This indicates that the n-p interaction is the major contributor to the difference between the calculated and the experimental binding energies.