One- and three-quasiparticle states in 171Hf and high spin rotational bands

Abstract

Abstract The 1 2 − [521] and 7 2 + [633] one-quasiparticle bands in the N = 99 nucleus 171Hf have been identified to spins of about 45 2 using (heavy ion, xn) reactions. The moments of inertia of these bands are consistent with the absence of backbending in the N = 98 core nucleus. The half-life of the 5 2 − [512] intrinsic state was measured as 63.6 ns. The strength of the 5 2 − [512] → 7 2 + [633] E 1 transition is discussed. Two three-quasiparticle isomers with spins and parities 19 2 + and 23 2 − have been identified and their suggested configurations are a 7 2 + [633] neutron added to the 6+ and 8− two-quasiproton states of the core. The moment of inertia of a rotational band based on the 23 2 − isomer supports this suggestion, and shows the effect of partial rotation alignment of the i 13 2 neutron.