Distinct ground state features and the decay chains of Z = 121 Superheavy Nuclei

TL;DR

This paper systematically studies the ground state properties and decay chains of Z=121 superheavy nuclei using relativistic and macroscopic-microscopic models, revealing shell closures, bubble-like structures, and decay modes with results aligning well with existing data.

Contribution

It provides a comprehensive theoretical analysis of Z=121 isotopes, identifying magic numbers, structural features, and decay pathways with novel insights into superheavy nuclear stability.

Findings

Identification of shell closures at N=164 and 228.

Observation of bubble-like charge density depletion.

Predicted alpha decay chains consistent with experimental data.

Abstract

A fully systematic study of even and odd isotopes (281 $\leq$ A $\leq$ 380) of Z = 121 superheavy nuclei is presented in theoretical frameworks of Relativistic mean-field plus state dependent BCS approach and Macroscopic-Microscopic approach with triaxially deformed Nilson Strutinsky prescription. The ground state properties namely shell correction, binding energy, two- and one- proton and neutron separation energy, shape, deformation, density profile and the radius are estimated that show strong evidence for magicity in N = 164, 228. Central depletion in the charge density due to large repulsive Coulomb field indicating bubble-like structure is reported. A comprehensive analysis of the possible decay modes specifically $\alpha$-decay and spontaneous fission (SF) is presented and the probable $\alpha$-decay chains are evaluated. Results are compared with FRDM calculations and the available experimental data which show excellent agreement.