Systematic study on α-decay half-lives. A new dependency of effective sharp radius on α-decay energy

Within the framework of the proximity formalism, we present a systematic study to analyze the effects of the α-decay energy through the effective sharp radius parameter on the α-decay half-lives of 227 nuclei in the range 61≤Z≤99. Wentzel-Kramers-Brillouin (WKB) calculations with the proximity potential Zhang 2013 are carried out to obtain the theoretical values of the α-decay half-lives. In this work, we introduce a new Q${}_{\alpha }$-dependent (QD) form of the effective sharp radius which significantly reduces the standard deviation of estimated half-lives using the Zhang 2013 model in comparison with the corresponding experimental data in our selected mass range. We evaluate the validity of this simple formula using the Geiger-Nuttall (G-N) plots and semi-empirical formulas. The modified form of the Zhang 2013 model is also found to work well in α-decay studies of superheavy nuclei (SHN) with Z=117-120. Our results reveal that the calculated half-lives for the use of new proposed form of the effective sharp radius in the proximity potential can reproduce the closed-shell effects at neutron magic number N=126 and N=184.