Unified Royer law revision for alpha-decay half-lives: shell corrections, pairing,and orbital-angular-momentum

TL;DR

This paper introduces an improved empirical Royer law for alpha-decay half-lives, incorporating shell corrections, pairing, and orbital angular momentum, significantly enhancing predictive accuracy with fewer parameters.

Contribution

The authors develop a unified Royer law with only four parameters, including new terms for shell effects and pairing, reducing complexity and improving accuracy over previous models.

Findings

Root-mean-square deviation reduced from 0.520 to 0.279

Parameter count decreased by 66.7%

Enhanced predictions for superheavy nuclei

Abstract

The Royer law is a widely used empirical relation for calculating alpha-decay half-lives; however, it requires 12 parity-dependent parameters.It exhibits systematic deviations near the shell closure. We propose an improved Royer law by adding a shell-correction term, an odd-even pairing indicator, and an orbital-angular-momentum contribution. This unified framework reduces the number of free parameters to just four, leading to significant improvements in accuracy. The root-mean-square deviation across 550 experimental data points decreases from 0.520 to 0.279, corresponding to a 66.7% reduction in parameters and 46.3% improvement in accuracy. Using this refined formalism, we predict alpha-decay half-lives for superheavy nuclei with atomic numbers.