Pairing effect on critical spin in chiral rotation. II. Triaxial deformation dependence

The critical spin Ic or critical frequency ℏωc denotes the minimum spin or rotational frequency required for the onset of aplanar chiral rotation in nuclear systems. The triaxial deformation dependence of the pairing effect on Ic and ℏωc are investigated for the particle-hole configuration π(1h11/2) - ν(1h11/2)-1, with triaxial deformation parameters γ=15, 20, 25, 35, 40, and 45, within the particle rotor model. The analyses of the energy-splitting ΔE(I) between the doublet bands, the probability density profiles P(θ,φ) of the total angular momentum orientation (θ,φ), the maximal and average orientation angles φm and φ¯, as well as the derived rotational frequency ℏω(I) reveal that with increasing neutron pairing interaction, the critical spin Ic is delayed for γ<30, whereas it is advanced for γ>30. In contrast, the critical frequency ℏωc decreases monotonically across all values of γ. These behaviors are further elucidated by analyzing the angular momentum components of both protons and neutrons along the three principal axes.