High-$K$ multi-particle bands and pairing reduction in $^{254}$No

TL;DR

This paper investigates the rotational properties and multi-particle states of $^{254}$No using the cranked shell model with particle-number conserving pairing, revealing insights into pairing reduction and shell gaps.

Contribution

First theoretical study of rotational bands on top of specific two-particle states and pairing reduction in $^{254}$No using a particle-number conserving approach.

Findings

Reproduces experimental excitation energies and moments of inertia.

Including high-order deformation improves agreement with data.

Pairing reduction due to Pauli blocking explains the rise in moments of inertia.

Abstract

The multi-particle states and rotational properties of two-particle bands in $^{254}$No are investigated by the cranked shell model (CSM) with pairing correlations treated by a particle-number conserving (PNC) method. For the first time, the rotational bands on top of two-particle $K^{\pi}=3^+,8^-$ and $10^+$ states and the pairing reduction are studied theoretically in $^{254}$No. The experimental excitation energies and moments of inertia for the multi-particle state are reproduced well by the calculation. Better agreement with the data are achieved by including the high-order deformation $\varepsilon_{6}$ which leads to enlarged $Z=100$ and $N=152$ deformed shell gaps. The rise of the $J^{(1)}$ in these two-particle bands compared with the ground-state band is attributed to the pairing reduction due to the Pauli blocking effects.