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

A new a preformation factor formula was proposed in the framework of unified fission model (UFM), the coefficients of the formula were obtained by fitting the extracted alpha preformation factors of 465 nuclei with Z = 62 - 103. The root mean square (RMS) deviation of the calculated alpha preformation factors with the extracted values is 0.388, indicating that the formula can describe the alpha particle preformation probability reliably. Then the alpha decay half-lives for recently observed 76 superheavy nuclei (SHN) are calculated by the UFM with the new alpha 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 alpha decay half-lives of SHN. Encouraged by this, the predictions of alpha decay half-lives for SHN Z = 119, 120 isotopes are made by using the theoretical mass tables FRDM2012, WS4 and WS 2016+RBFs to determine the Q(alpha) values. The predictions can provide references for experiments of synthesizing new SHN if the mass tables are accurate enough. (C) 2021 Elsevier B.V. All rights reserved.