Nucleonic Localisation And Alpha Radioactivity

Relativistic energy density functional approaches are known to well describe nuclear states which involve alpha clusters. Here, alpha emitting nuclei are analyzed through the behavior of the spatial localisation of nucleonic states, calculated with an axially deformed relativistic Hartree-Bogoliubov approach over the nuclear chart. The systematic occurrence of more localised valence states, having an n = 1 radial quantum number, allows to pinpoint nuclei in agreement with experimentally known alpha-emitters. The cases of Po-212 and Te-104 are investigated, showing the concomitant contributions of the pseudospin symmetry and the presence of n = 1 states, on the alpha preformation probability. The impact of the localisation of valence states, on alpha preformation probability, is then analyzed. It allows to study shell effects on this probability, over isotopic and isotonic chains. Finally, a phenomenological law is also provided, relating this probability to the radial quantum number of the valence states.