A new derivation of symmetry energy from nuclei beyond the \beta-stability line

TL;DR

This paper introduces a direct method to derive nuclear symmetry energy from chemical potential shifts in nuclei beyond beta-stability, revealing shell oscillations and refining symmetry energy component estimates.

Contribution

It presents a novel direct derivation procedure for symmetry energy from chemical potential differences, challenging previous claims of large symmetry energy at A≈100.

Findings

Detected strong shell oscillations (~15%) in symmetry energy coefficient

Refuted previous reports of exceptionally large symmetry energy at A≈100

Estimated surface-to-volume ratio of symmetry energy as approximately 1.7

Abstract

We suggest the procedure of direct derivation of the symmetry energy from the shift of neutron-proton chemical potentials \Delta\lambda=\lambda_{n}- \lambda_{p} for nuclei beyond the beta-stability line. We observe the presence of anomalous strong (about 15%) shell oscillations at the symmetry energy coefficient b_{sym}. Our results do not confirm the existence of exceptionally large values of the symmetry energy coefficient at mass number A\approx 100 which was earlier reported in Ref.[2]. Using the fitting procedure, we have evaluated the volume, b_{sym,vol}, and surface, b_{sym,surf}, contributions to the symmetry energy. We have estimated the experimental value of surface-to-volume ratio as r_{S/V}=|b_{sym,surf}}|/b_{sym,vol}\approx 1.7 for the fitting interval A\geq 50.