Neutron-skin thickness determines the surface tension of a compressible nuclear droplet

TL;DR

This paper explores how neutron-skin thickness influences the surface tension in a compressible nuclear droplet, using a systematic model to connect microscopic and macroscopic nuclear properties and constrain the nuclear equation of state.

Contribution

It introduces a comprehensive model incorporating surface tension and diffuseness corrections, validated against microscopic calculations, to better understand neutron-skin thickness and nuclear matter properties.

Findings

Surface tension is crucial for linking microscopic and macroscopic nuclear models.

The model accurately reproduces neutron-skin thickness evolution across isotopes.

Constraints on the equation of state parameters are improved through this analysis.

Abstract

We systematically investigate the neutron-skin thickness of neutron-rich nuclei within a compressible droplet model, which includes several parameters characterizing the surface tension and the equation of state (EOS) of asymmetric nuclear matter as well as corrections due to the surface diffuseness. Such a systematic analysis helps towards constraining the EOS parameters of asymmetric nuclear matter and the poorly known density dependence of the surface tension; the latter is estimated with help of available experimental data for the neutron and proton density distributions and the nuclear masses. Validity of the present approach is confirmed by calculating realistic density distributions of Ca, Ni, Zr, Sn, Yb, and Pb isotopes within a microscopic Skyrme-Hartree-Fock+BCS method for various sets of the effective nuclear force. Our macroscopic model accompanied by the diffuseness corrections works well in the sense that it well reproduces the evolution of the microscopically deduced neutron-skin thickness with respect to the neutron number for selected sets of the effective nuclear force. We find that the surface tension of the compressible nuclear droplet is a key to bridging a gap between microscopic and macroscopic approaches.