Robustness of N=152 and Z=108 shell closures in superheavy mass region*

Abstract The neutron shell gap at has been experimentally confirmed through high-precision mass measurements on nobelium ( ) and lawrencium ( ) isotopes. The experimental measurements on α -decay properties suggest that deformed doubly-magic nature of Hs. However, the magic gaps in the superheavy region are generally expected to be fragile. In this study, we test the robustness of shell closure in isotones and shell closure in Hs isotopes by employing an alternative approach where both theoretical analysis and available experimental data are required. Combined with existing experimental measurements on α -decay energies, it is determined that robust neutron shell persists at least in isotopes, and robust proton shell persists in Hs isotopes with . Additionally, the relativistic mean-field model is determined as unable to provide shell. Thus, the conclusion that robust shell exists at least in isotopes, provides crucial benchmarks for constraining effective interactions suitable for superheavy nuclei in nuclear energy-density functional theory in future.