Nuclear chiral rotation induced by superfluidity

TL;DR

This paper investigates how superfluidity influences nuclear chiral rotation, revealing that pairing correlations facilitate earlier chiral rotation by modifying particle alignments, using advanced covariant density functional theory.

Contribution

It introduces a shell-model-like approach with exact particle number conservation to study superfluid effects on nuclear chiral rotation, applied to Nd135.

Findings

Superfluidity reduces the critical frequency for chiral rotation.

Pairing correlations enhance the preference for rotation along the intermediate axis.

Chiral rotation appears earlier due to reduced particle/hole alignments.

Abstract

The microscopic understanding on the influence of the pairing correlations or the superfluidity on the nuclear chiral rotation has been a longstanding and challenging problem. Based on the three-dimensional cranking covariant density functional theory, a shell-model-like approach with exact particle number conservation is implemented to take into account the pairing correlations and applied for the chiral doublet bands in Nd135. The data available are well reproduced. It is found that the superfluidity can reduce the critical frequency and make the chiral rotation easier. The mechanism is that the particle/hole alignments along the short/long axis are reduced by the pairing correlations, resulting in the enhanced preference of the collective rotation along the intermediate axis, and inducing the early appearance of the chiral rotation.