Systematic of signature inversion in (h 11/2)p⊗(i 13/2)n for odd–odd nuclei in rare-earth nuclei

Abstract

Systematic features of the signature inversion phenomenon in (h 11/2)p ⊗(i 13/2)n in doubly-odd rare-earth nuclei are presented. These features are generally observed in high-j orbitals, mainly, in (h 9/2),(h 11/2) and (i 13/2). Calculations are carried out within the framework of the two quasiparticle plus rotor model (TQPRM) to explain strong odd–even staggering and signature inversion observed in these high-j orbitals. The shifting of point of inversion to lower/higher spin with the increase in neutron/proton numbers is well explained by the calculations. It is found that 1 /2[541] proton orbital of h 9/2 is necessary in the lower mass region to obtain the point of inversion.