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

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.

Comments: 6 figures