Modification of Even-A Nuclear Mass Formula

Jingyi Zhang

doi:10.4236/jamp.2017.511187

Abstract

In this paper we obtain an empirical mass formula of even-A nuclei based on residual proton-neutron interactions. The root-mean-squared deviation (RMSD) from experimental data is at an accuracy of about 150 Kev. While for heavy nuclei, we give another formula that fits the experimental data better (RMSD ≈ 119 Kev). We have successfully described the experimental data of nuclear masses and predicted some unknown masses (like 200Ir not involved in AME2003, the deviation of our predicted masses from the value in AME2012 is only about 82 keV). The predictive power of our formula is more competitive than other mass models.

Highlights

The study of nuclear masses and energy levels has always been one of the most challenging frontiers in the field of nuclear physics
We have successfully described the experimental data of nuclear masses and predicted some unknown masses
We find our formula has a good performance in describing the nuclear masses

Summary

Introduction

The study of nuclear masses and energy levels has always been one of the most challenging frontiers in the field of nuclear physics. The local mass relations, such as the isobaric multiplet mass equation (IMME), the Garvey-Kelson (GK) relations, which use the predicted nuclear masses and the residual proton-neutron interactions to evaluate the mass. Our purpose is to obtain a residual proton-neutron interactions formula of even-A nuclei from those of neighboring nuclei. The RMSD from experimental data is about 150 Kev. And for heavy nuclei, we obtain another formula fits with the experimental data even more precise. With our further refinement of heavy nuclei, the RMSD gets even smaller to about 120 Kev. In Section III we successfully predict some unknown masses.

The Residual Proton-Neutron Interactions

62.78 A keV for even-A nuclei with

Mass Predictions

Discussion and Conclusions