Self-consistent three-dimensional cranking calcutation based on HFB. Tilted axis rotation in 182Os

Abstract

Abstract A self-consistent three-dimensional cranking calculation based on the Hartree-Fock-Bogoliubov method was performed. By carrying out a more careful and thorough calculation for 182Os than before we confirm the previous result demonstrating the existence of solutions of tilted axis uniform rotation in the yrast band in a model hamiltonian. The tilted axis rotation appears at J = 14 h in the g-band and continues to survive up to the higher angular momentum states in the s-band. The respective roles of terms in the hamiltonian were analyzed. The driving force of the tilted axis rotational motion turns out to originate in the Qμ−±2 moment due to the natural parity proton and neutron orbitals, rather than the intruder orbitals. The one-body part of the hamiltonian acts as a restoring force against the motion. The balance between these two forces accounts for the new stable rotational motion in this nucleus. The axis of uniform rotation lays on the prime meridian in all the cases. We found the energy surfaces to have d4h-symmetry in the three-dimensional angular momentum space. The γ-deformation turns out to be anti-symmetric with respect to the meridian at longitude θ ≡ 55° mod 90°. The north and south poles are degenerate local minima in energy surface for J = 8 h sphere and correspond to the “K = 8 band” head state. The calculated excitation energy for the points is comparable with the observed one.