Correlation between alpha-decay half-lives and symmetry energy

TL;DR

This study investigates the relationship between alpha-decay half-lives of certain nuclei and the nuclear symmetry energy, using various models to connect nuclear properties with neutron star observations.

Contribution

It introduces a correlation analysis between alpha-decay half-lives and symmetry energy stiffness using KIDS models calibrated with nuclear and neutron star data.

Findings

Alpha-decay half-lives increase with the stiffness of the symmetry energy.

The correlation is explained by the influence of symmetry energy on particle distribution.

Models with different symmetry energy parameters show systematic variation in decay half-lives.

Abstract

We study the alpha-decay half-lives of 84 <= Z <= 92 even-even nuclei in the semiclassical WKB approximation framework using the density-dependent cluster model and the density distribution described by various Korea-IBS-Daegu-SKKU (KIDS) models. Main goal of this work is to find a correlation between the alpha-decay half-lives and the stiffness of the symmtery energy. Parameters of KIDS model are determined to reproduce the nuclear data (energy and charge radii of 40Ca, 48Ca and 208Pb) and the neutron star observations including constraints by NICER, tidal deformability from GW170817, and the maximum mass limit of neutron star observations. We use the KIDS models (A-D) which have distinctive values for the parameters controlling the stiffness of the nuclear matter equation of state. We find that the alpha-decay half-lives increase systematically from KIDS-A model to KIDS-D model. This implies a correlation between the alpha-decay half-lives and the symmetry energy. We find that the correlation can be understood from the dependence of the particle distribution in the core and the surface region on the symmetry energy.