Nuclear structure in 95,97Ru nuclei

Abstract

The high-spin level structures of the nuclei 95,97Ru have been studied via the 92Mo(6Li,p2n)95Ru and 93Nb(7Li,3n)97Ru reactions, using γ-γ coincidence, γ-W(θ), and pulsed-beam-γ measurements. Shell-model calculations of energy levels and B(E2) values for 95Ru have been performed and compared with the experimentally observed levels and the measured (21/2)+ and (17/2)+ lifetimes. A collective ΔJ=2 band has been identified with the 1h11/2 neutron state in 97Ru, and discussed in the context of the general nature of collectivity in nuclei outside the N=50 closed shell. No ΔJ=1 band associated with the 1g9/2 neutron-hole intruder state was found in either of the N=51,53 Ru nuclei, as observed previously for the 1g9/2 proton-hole intruder states in the Z=51 Sb and Z=53 I nuclei.