Pairing and rotational properties of actinides and superheavy nuclei in covariant density functional theory

TL;DR

This study uses covariant density functional theory with the CRHB approach to systematically analyze pairing and rotational properties of actinides and superheavy nuclei, revealing the need to attenuate pairing strength and highlighting the importance of deformation effects.

Contribution

First systematic application of covariant density functional theory to study pairing and rotational properties of actinides and superheavy nuclei, including odd-even mass staggering indicators.

Findings

Experimental data are well described for most nuclei.

Attenuation of the pairing force is necessary for accurate modeling.

Evidence suggests octupole deformation stabilization at high spin.

Abstract

The cranked relativistic Hartree-Bogoliubov (CRHB) theory has been applied for a systematic study of pairing and rotational properties of actinides and light superheavy nuclei. Pairing correlations are taken into account by the Brink-Booker part of finite range Gogny D1S force. For the first time in the covariant density functional theory (CDFT) framework the pairing properties are studied via the quantities (such as three-point $\Delta^{(3)}$ indicators) related to odd-even mass staggerings. The investigation of the moments of inertia at low spin and the $\Delta^{(3)}$ indicators shows the need for an attenuation of the strength of the Brink-Booker part of the Gogny D1S force in pairing channel. The investigation of rotational properties of even-even and odd-mass nuclei at normal deformation, performed in the density functional theory framework in such a systematic way for the first time, reveals that in the majority of the cases the experimental data are well described. These include the evolution of the moments of inertia with spin, band crossings in the $A\geq 242$ nuclei, the impact of the particle in specific orbital on the moments of inertia in odd-mass nuclei. The analysis of the discrepancies between theory and experiment in the band crossing region of $A\leq 240$ nuclei suggests the stabilization of octupole deformation at high spin, not included in the present calculations. The evolution of pairing with deformation, which is important for the fission barriers, has been investigated via the analysis of the moments of inertia in the superdeformed minimum. The dependence of the results on the CDFT parametrization has been studied by comparing the results of the calculations obtained with the NL1 and NL3* parametrizations.