Microscopic triaxial cranking model: preliminary predictions for oscillator potential and light nuclei

TL;DR

This paper introduces a microscopic, quantal cranking model for triaxial nuclear rotation that incorporates dynamic angular velocity, providing more accurate predictions for light nuclei compared to traditional semi-classical models.

Contribution

The paper derives a new microscopic cranking model (MSCRM3) that accounts for dynamic angular velocity, improving upon the semi-classical CCRM3 for studying triaxial rotation in nuclei.

Findings

MSCRM3 predicts differences in rotational features compared to CCRM3.

Dynamic angular velocity significantly impacts high-spin and back-bending phenomena.

Preliminary results for light nuclei show the importance of microscopic effects.

Abstract

The conventional cranking model for uniaxial and triaxial rotation (CCRM3) is frequently used to study rotational features in deformed nuclei. However, CCRM3 is semi-classical and phenomenological because it uses a constant angular velocity, resulting in a number of Hamiltonian symmetry breakings. To investigate the effect of a dynamic angular velocity, a quantal, microscopic, D2, signature, and time-reversal invariant cranking model for triaxial rotation (MSCRM3) is derived exactly from a unitary rigid-flow-velocity-field rotation transformation of the nuclear Schrodinger equation and Hartree-Fock method. Except for a microscopically-determined angular velocity and normally-small residual terms, the MSCRM3 and CCRM3 Schrodinger equations are identical in form. The microscopic angular velocity emerges from the HF variation, and the residual terms may become significant for triaxial rotation at high spins and in back-bending regions where and undergo large changes. A preliminary application of MSCRM3 and CCRM3 to the light nuclei 20Ne, 24Mg, and 28Si using the simple self-consistent deformed harmonic oscillator potential predicts some interesting differences between the rotational features and phenomena predicted by the two models. These differences are attributable to the impact of the dynamic angular velocity. It is important to investigate and understand these differences for the simple and realistic nuclear interactions.