Rotational bands in neutron-rich ^160,161,162Ho

Abstract.

High-spin states in ^160,161,162Ho have been populated in the reactions ^158,160Gd(⁷Li, xn) at 56 MeV. In all three isotopes the known rotational bands have been extended to significantly higher spin. In ¹⁶⁰ Ho, the band crossing in the $\pi$7/2^-[523] $\otimes$ $\nu$11/2^-[505] band has been observed for the first time. The sequences built on the proton 7/2^-[523], 7/2 ⁺ [404], 1/2 ⁺ [411] and 1/2^-[541] states in ¹⁶¹Ho have been extended up to spin 51/2^-, 35/2 ⁺ , 51/2 ⁺ and 41/2^-, respectively, leading to the first observation of upbends in all four cases. In addition, a new band most probably belonging to this nucleus has been identified. In the most neutron-rich isotope ¹⁶²Ho, the only known rotational band, which is built on the $\pi$7/2^-[523] $\otimes$ $\nu$5/2 ⁺ [642] configuration, has been extended up to the 28^- state. The properties of all observed bands are discussed and compared to the neighbouring isotopes.