Predictions for the α decay of superheavy nuclei of Z = 119 − 120 isotopes

Abstract

A new α preformation factor formula was proposed in the framework of unified fission model (UFM), the coefficients of the formula were obtained by fitting the extracted α preformation factors of 465 nuclei with Z=62−103. The root mean square (RMS) deviation of the calculated α preformation factors with the extracted values is 0.388, indicating that the formula can describe the α particle preformation probability reliably. Then the α decay half-lives for recently observed 76 superheavy nuclei (SHN) are calculated by the UFM with the new α preformation factor formula. The comparison between the calculated values and the experimental data demonstrates that the UFM taking the preformation factor into account is a useful tool to investigate the α decay half-lives of SHN. Encouraged by this, the predictions of α decay half-lives for SHN Z=119,120 isotopes are made by using the theoretical mass tables FRDM2012, WS4 and WS2016+RBFs to determine the Qα values. The predictions can provide references for experiments of synthesizing new SHN if the mass tables are accurate enough.