Multiquasiparticle states in the neutron-rich nucleus174Tm

Deep inelastic and transfer reactions with an 820-MeV, Xe-136 beam and various ytterbium and lutetium targets have been employed to study high-spin structures in the neutron-rich thulium isotopes beyond Tm-171. Results in the doubly odd nucleus, Tm-174, include the identification of numerous new two-and four-quasiparticle intrinsic states including several isomers below 1 MeV, and the observation of the K-pi = 4(-) ground state rotational band populated via direct decay from a tau = 153(10)-mu s, K-pi = 14(-) isomer at 2092 keV. The 398-keV, M1 transition linking the isomer and ground state band is abnormally fast for a highly forbidden, Delta K = 10 decay. This relative enhancement is explained in terms of mixing of the 13(-) level with the nearby 13(-) member of a K-pi = 8(-) rotational band, with an interaction strength of V approximate to 1.4 keV. Multiquasiparticle calculations are compared with the observed states.