Nuclear Jacobi and Poincar\'e Transitions at High Spins and Temperatures: Account~of~Dynamic~Effects~and~Large-Amplitude Motion

TL;DR

This paper analyzes high-spin nuclear shape transitions, specifically Jacobi and Poincaré types, using a realistic liquid drop model, accounting for large-amplitude oscillations and their impact on nuclear energy landscapes.

Contribution

It introduces an approximate collective Schrödinger equation approach to study shape transitions and large-amplitude motions in high-spin nuclei within the LSD model.

Findings

Identification of critical spin values for shape transitions

Large-amplitude oscillations significantly influence transition dynamics

Energy landscape flattening facilitates shape coexistence

Abstract

We present a theoretical analysis of the competition between so-called nuclear Jacobi and Poincar\'e shape transitions in function of spin - at high temperatures. The latter condition implies the method of choice - a realistic version of the nuclear Liquid Drop Model (LDM), here: the Lublin-Strasbourg Drop (LSD) model. We address specifically the fact that the Jacobi and Poincar\'e shape transitions are accompanied by the flattening of total nuclear energy landscape as function of the relevant deformation parameters what enforces large amplitude oscillation modes that need to be taken into account. For that purpose we introduce an approximate form of the collective Schr\"odinger equation whose solutions are used to calculate the most probable deformations associated with both types of transitions and discuss the physical consequences in terms of the associated critical-spin values and transitions themselves.