Band Structures of $^{182}$ Os Studied by GCM based on 3D-CHFB

Abstract

Band structure properties of $^{182}$Os are investigated through a particle number and angular momentum constrained generator coordinate(GCM) calculation based on self-consistent three-dimensional cranking solutions. From the analysis of the wave function of the lowest GCM solution, we confirm that this nucleus shows a tilted rotational motion in its yrast states, at least with the present set of force parameters of the pairing-plus-quadrupole interaction Hamiltonian. A close examination of behavior of other GCM solutions reveals a sign of a possible occurrence of multi-band crossing in the nucleus. Furthermore, in the course of calculations, we have also found a new potential curve along the prime meridian on the globe of the $J=18\hbar$ sphere. Along this new solution the characters of proton and neutron gap parameters get interchanged. Namely, $\Delta_p$ almost vanishes while $\Delta_n$ grows to a finite value close to the one corresponding to the principal axis rotation(PAR). A state in the new solution curve at the PAR point turns out to have almost the same characteristic features of an yrare $s$-band state which gets located just above the $g$-band in our calculation. This fact suggests a new type of seesaw vibrational mode of the proton and the neutron pairing, occurring through a wobbling motion. The mode is considered to bridge the $g$-band states and the $s$-band states in the backbending region.