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

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.