The α-particle clustering and half-lives of the newly discovered 207,208Th decay chains within relativistic-Hartree-Bogoliubov approach

The structural and decay properties of the ground state of recently discovered neutron-deficient 207Th and remeasured 208Th isotopes Yang et al. (2022) [26] is examined using the Relativistic-Hartree-Bogoliubov (RHB) formalism using the DD-ME2 parameter set within the preformed cluster-decay model (PCM). The relativistic medium-dependant R3Y so-called DD-R3Y NN potentials are for the first time used to obtain the nucleus-nucleus potential as input into the PCM. The penetration probability is calculated using the WKB approximation, and the preformation probability (P alpha) is estimated using our newly derived formula, which is based on parameters well known to influence the alpha -particle radioactivity. A close correlation is observed between the alpha-preformation factor and the crucial role of the pairing correlation in the alpha-decay process. Furthermore, the P alpha values for the even-even nuclei are generally found to be of higher magnitude than those for the odd-A nuclei. Our results further affirm that the odd-even staggering effect on the Q alpha values and its accompanying effects on other observables such as the charge radii and the decay half-lives, which can be largely attributed to the pairing correlation and Pauli blocking of the unpaired valence nucleons.

Automated summary

The ground state properties and decay features of the newly discovered neutron-deficient 207Th and remeasured 208Th isotopes are investigated using the Relativistic-Hartree-Bogoliubov (RHB) formalism within the preformed cluster-decay model (PCM). The nucleus-nucleus potential is obtained using the DD-R3Y NN potentials for the first time as input into the PCM. The alpha preformation probability is calculated based on established parameters, showing a close correlation with the role of pairing correlation in the alpha-decay process. The results also reveal the influence of odd-even staggering effect on various observables, attributed to the pairing correlation and Pauli blocking of unpaired valence nucleons.