Temperature induced shell effects in deformed nuclei

Abstract

The thermal evolution of the shell-correction energy is investigated for deformed nuclei using Strutinsky prescription in a self-consistent relativistic mean-field framework. For temperature independent single-particle states corresponding to either spherical or deformed nuclear shapes, the shell-correction energy ${\ensuremath{\Delta}}_{\mathrm{sc}}$ steadily washes out with temperature. However, for states pertaining to the self-consistent thermally evolving shapes of deformed nuclei, the dual role played by the single-particle occupancies in diluting the fluctuation effects from the single-particle spectra and in driving the system towards a smaller deformation is crucial in determining ${\ensuremath{\Delta}}_{\mathrm{sc}}$ at moderate temperatures. In rare-earth nuclei, it is found that ${\ensuremath{\Delta}}_{\mathrm{sc}}$ builds up strongly around the shape transition temperature; for lighter deformed nuclei like ${}^{64}\mathrm{Zn}$ and ${}^{66}\mathrm{Zn},$ this is relatively less prominent.