Studies on α and cluster radioactivity using the improved universal (UNIV) curve

Abstract

In this article, we modified the universal (UNIV) formula of Poenaru et al. [Phys. Rev. C 83, 014601 (2011)] by including the disintegration energy dependent formula as a preformation factor. The improved universal formula (Imp UNIV) is applied to α decay of 309 heavy nuclei in the region Z=74-93 and found that the standard deviation  of decimal logarithmic half-life decreased from 0.64312 (UNIV) to 0.56467 (Imp UNIV). It is also observed that  value decreased from 0.70502(UNIV) to 0.68189 (Imp UNIV) in the case of cluster radioactivity showing improvement of present formalism Imp UNIV over UNIV in reproducing experimental half-lives of α and cluster radioactivity of heavy nuclei. The α decay half-lives of 80 superheavy nuclei (SHN) with Z  104have also been investigated by UNIV and Imp UNIV formula and the  value is found as 1.10681 and 0.69399 respectively, which shows that experimental α half-lives of SHN can be reproduced well by using Imp UNIV formula. The plot connecting the sum of decimal logarithm of half-life and preformation factor, log10 T1/ 2 (s) log10 S versus decimal logarithm of external penetrability,  log10 Ps for Imp UNIV is found linear for both α and cluster radioactivity with the same slope and intercept showing the universal nature of the curve. The good agreement between our predictions on α decay of Og (Z=118) isotopes with the generalized liquid drop model (GLDM) and Royer formula also reveals the reliability of our formalism. The neutron shell closure at N = 184 and N ≈ 200 are evident in our study. The prediction of the unobserved α and cluster radioactivity performed in this study will be helpful for future experiments.