Predictions of Alpha Decay Half lives of Heavy and Superheavy Elements

Abstract

Theoretical estimates for the lifetimes of several isotopes of heavy elements with Z=102-120 are presented by calculating the quantum mechanical tunneling probability in a WKB framework and using microscopic nucleus-nucleus potential obtained by folding the densities of interacting nuclei with the DDM3Y effective nuclear interaction. The $α$-decay half lives calculated in this formalism using the experimental $Q$-values are in good agreement over a wide range of experimental data. Half lives are also calculated using $Q$-values extracted from two mass formulae. The Viola-Seaborg-Sobiczewski (VSS) estimates of $α$-decay half lives with the same $Q$-values are presented for comparison. The half life calculations are found to be quite sensitive to the choice of $Q$-values. Comparison with the experimental data delineates the inadequacies of older mass predictions in the domain of heavy and superheavy elements as compared to the newer one by Muntian-Hofmann-Patyk-Sobiczewski, and highlights necessity of a more accurate mass formula which can predict $Q$-values with even higher precision.

18 pages including 5 figures and 1 table