Analytical description of the excited state phase transition to octupole deformed shape in alternating parity bands

TL;DR

This paper presents an analytical model describing the phase transition from octupole vibrations to stable octupole deformation in heavy nuclei, aligning well with experimental data across multiple isotopes.

Contribution

It introduces a universal analytical description of parity splitting and electric dipole transitions during the shape phase transition in heavy nuclei.

Findings

Good agreement with experimental data for Ra, Th, U, and Pu isotopes.

Single critical angular momentum parameter characterizes the phase transition.

Analytical expressions effectively describe parity splitting and electric dipole moments.

Abstract

Angular momentum dependences of the parity splitting and electric dipole transitions in the alternating parity bands of heavy nuclei have been analyzed. It is shown that these dependences can be treated in a universal way with a single parameter of critical angular momentum, which characterizes phase transition from octupole vibrations to the stable octupole deformation. Using the simple but useful model of axially-symmetric reflection-asymmetric mode, the analytical expression for the parity splitting and electric dipole transitional moment have been obtained. The results obtained are in a good agreement with the experimental data for various isotopes of Ra, Th, U, and Pu.