Structure and reaction study of Z=120 isotopes using non-relativistic and relativistic mean-field formalism

TL;DR

This study compares relativistic and non-relativistic models to analyze the stability, surface properties, and reaction cross-sections of superheavy Z=120 isotopes, highlighting the N=184 shell closure and stability features.

Contribution

It provides a comprehensive comparison of E-RMF and SHF approaches for superheavy nuclei, including surface properties and reaction cross-sections, revealing the stability of Z=120 isotopes at N=184.

Findings

Symmetry energy peaks at N=182 (SHF) and N=184 (E-RMF).

Enhanced reaction cross-section indicates extra stability of $^{304}120$.

Shell closure at N=184 confirmed by stability analysis.

Abstract

An extensive study is carried out for the island of stability in the superheavy nuclei of Z=120 and N=164-220 within the effective field theory motivated relativistic mean-field (E-RMF) and the non-relativistic Skyrme-Hartree-Fock (SHF) approaches. The relativistic G3 and IOPB-I and non-relativistic SLy4 and SkMP parameter sets are used for the investigations. Surface properties such as symmetry energy, neutron pressure and the curvature coefficient of symmetry energy are discussed within the coherent density fluctuation model (CDFM) using the Skyrme and the Br\"uckner energy density functionals. The volume and surface contributions of symmetry energy are evaluated using Danielewicz's liquid drop approximation within the CDFM. The total nuclear reaction and elastic differential cross-sections are also obtained for both SHF and E-RMF within the Glauber model. The peaks in the symmetry energy at N = 182 for SHF and N=184 for E-RMF are seen, which are absent in the Br\"uckner functional. The shifting of peak in the symmetry energy with Br\"uckner functional can be correlated to the Coester-band problem. The enhanced total reaction cross-section for relativistic density of $^{304}120$ suggests the extra stability of this nucleus. This further confirms the shell/sub-shell closure of N = 184 in E-RMF force. The differential cross-section shows its force independent nature and significant increase with the scattering angle.