Transverse wobbling in an even-even nucleus

TL;DR

This paper reports the first observation of transverse wobbling motion in a two-quasiparticle band of an even-even nucleus, using advanced theoretical models to match experimental data.

Contribution

It introduces the first evidence of two-quasiparticle wobbling bands in an even-even nucleus, expanding understanding of nuclear wobbling phenomena.

Findings

Reproduces energy differences and electromagnetic transition ratios accurately.

Identifies the higher band as transverse wobbling motion.

First example of two-quasiparticle wobbling in an even-even nucleus.

Abstract

Two new bands built on the two-quasiparticle $\pi(h_{11/2})^2$ configuration of the even-even nucleus $^{130}$Ba are investigated using constrained triaxial covariant density functional theory combined with quantum particle rotor model calculations. The energy difference between the two bands, as well as the available electromagnetic transition probabilities $B(M1)_{\textrm{out}}/B(E2)_{\textrm{in}}$ and $B(E2)_{\textrm{out}}/B(E2)_{\rm{in}}$, are well reproduced. The analysis of the angular momentum geometry reveals that the higher band represents transverse wobbling motion of a two-quasiparticle configuration. This is the first example of two-quasiparticle wobbling bands in an even-even nucleus.