Systematic calculations ofα-decay half-lives with an improved empirical formula

Abstract

Based on the recent data in NUBASE2012, an improved empirical formula for evaluating the α-decay half-lives is presented, in which the hindrance effect resulted from the change of the ground state spins and parities of parent and daughter nuclei is included, together with a new correction factor for nuclei near the shell closures. The calculated α-decay half-lives are found to be in better agreements with the experimental data, and the corresponding root-mean-square (rms) deviation is reduced to 0.433 when the experimental Q-values are employed. Furthermore, the Q-values derived from different nuclear mass models are used to predict α-decay half-lives with this improved formula. It is found that the calculated half-lives are very sensitive to the Q-values. Remarkably, when mass predictions are improved with the radial basis function (RBF), the resulting rms deviations can be significantly reduced. With the mass prediction from the latest version of Weizsäcker-Skyrme (WS4) model, the rms deviation of α-decay half-lives with respect to the known data falls to 0.697.

Improved parametrization of the unified model forαdecay andαcapture

“…Similar rms errors obtained with the help of empirical relationships from Refs. [6,7,12,23,28] and UMADAC for these data subsets are also presented in Tables IV and V. Comparing the results in Tables IV and V we conclude that the empirical relationships (20) with parameters from Table III describe well the α-decay half-lives values in the dedicated subset of nuclei.…”

“…Similar rms errors obtained by using empirical relationships from Refs. [6,7,12,19,23,28] for our data set are also given in Table II. We use the same values of parameters in the formulas from Refs.…”

“…Since then, many other empirical relationships have been proposed by various authors; see, for example, Refs. [4,7,9,10,12,15,22,23,28] and papers cited therein.…”

“…That is why simple and accurate empirical relationships are still claimed. As a consequence, many empirical expressions have appeared during the last several decades [7,9,10,12,15,19,22,23,28]. The new extended data for the α-decay half-lives, atomic masses, and spins give the possibility of improving the accuracy of the empirical relationships introduced in Ref.…”

Systematic study ofαdecay half-lives for even-even nuclei within a two-potential approach

“…The traditional methods [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22]such as the WKB approximation, and empirical formulas [23][24][25][26] are constantly evolving. Among these methods the microscopic * Corresponding author:lixiaohuaphysics@126.com double-folding model adopting density dependent M3Y force and the liquid drop model adopting the proximity potential have been researched frequently.…”