First order shape transition and critical point nuclei in Sm isotopes from relativistic mean field approach

TL;DR

This study investigates shape phase transitions in Samarium isotopes using a relativistic mean field model, identifying critical point nuclei and analyzing their energy surfaces and single-particle spectra.

Contribution

It provides a microscopic analysis of shape transitions and critical point nuclei in Sm isotopes using multiple RMF interactions, highlighting the first order phase transition.

Findings

Identification of critical point nuclei: 148Sm, 150Sm, 152Sm.

Observation of a clear shape transition in potential energy surfaces.

Consistent results from single-particle spectra analysis.

Abstract

The critical point nuclei in Sm isotopes, which marks the first order phase transition between spherical U(5) and axially deformed shapes SU(3), have been investigated in the microscopic quadrupole constrained relativistic mean field (RMF) model plus BCS method with all the most used interactions, i.e., NL1, NL3, NLSH and TM1. The calculated potential energy surfaces show a clear shape transition for the even-even Sm isotopes with $N = 82\sim 96$ and the critical point nuclei are found to be $^{148}$Sm, $^{150}$Sm and $^{152}$Sm. Similar conclusions can also be drawn from the microscopic neutron and proton single particle spectra.