Probing collectivity in Zn isotopes with one particle or hole outside the N=40 subshell closure

The nuclear structure of the odd-mass Zn-69 and Zn-71 isotopes, with one hole or one particle outside the N = 40 subshell closure, has been investigated by measuring the lifetime of excited states using the recoil distance Doppler-shift method. The nuclei of interest were produced in a deep-inelastic reaction in inverse kinematics with a U-238 beam impinging on a Zn-70 target. Single-particle and collective states were found to coexist at low energy in Zn-69 and Zn-71.