Prolate-to-oblate transition and backbending along the yrast line induced by quasiparticle alignment

TL;DR

This paper investigates the shape transitions in Kr isotopes along the yrast line, highlighting the role of quasiparticle alignment in causing prolate-to-oblate shape changes and backbending phenomena.

Contribution

It introduces a beyond mean field approach that incorporates quasiparticle alignment and shape coexistence to explain shape transitions in Kr isotopes.

Findings

Quasiparticle orbitals induce sharp backbending in $^{82}$Kr.

Shape evolution from prolate to oblate is driven by quasiparticle alignment.

Quasiparticle effects are crucial for understanding yrast line behavior.

Abstract

The yrast lines in Kr isotopes with $N=42$, 44, and 46 are investigated in a beyond mean field framework with both prolate-oblate coexistence and quasiparticle alignment taken into account. Quasiparticle orbitals with high-$j$ and low-$\Omega$ on the oblate side are shown to be responsible for the sharp backbending observed in $^{82}$Kr, by driving the yrast shape from prolate to oblate. This suggests that quasiparticle alignment may not be neglected in the investigation of the shape evolution along the yrast line.