Particle-number conserving analysis of rotational bands in 247,249Cm and 249Cf

TL;DR

This paper uses a particle-number conserving cranked shell model to analyze high-spin rotational bands in odd-A nuclei 247, 249Cm and 249Cf, accurately reproducing experimental moments of inertia and elucidating the level crossing mechanisms.

Contribution

It introduces a particle-number conserving approach to study rotational bands, providing a more precise understanding of level crossings and alignments in these nuclei.

Findings

Reproduces experimental moments of inertia and alignments accurately.

Clarifies the level crossing and upbending mechanisms.

Analyzes the occupation probabilities of cranked Nilsson orbitals.

Abstract

The recently observed high-spin rotational bands in odd-$A$ nuclei $^{247, 249}$Cm and $^{249}$Cf [Tandel \textit{et al.}, Phys. Rev. C 82 (2010) 041301R] are investigated by using the cranked shell model (CSM) with the pairing correlations treated by a particle-number conserving (PNC) method in which the blocking effects are taken into account exactly. The experimental moments of inertia and alignments and their variations with the rotational frequency $\omega$ are reproduced very well by the PNC-CSM calculations. By examining the $\omega$-dependence of the occupation probability of each cranked Nilsson orbital near the Fermi surface and the contributions of valence orbitals to the angular momentum alignment in each major shell, the level crossing and upbending mechanism in each nucleus is understood clearly.