New, low-lying levels in the odd-odd, N = Z nucleus Ga-62 have been identified using a sensitive technique, where in-beam gamma rays from short-lived nuclei are tagged with beta decays following recoil mass identification. A comparison of the results with shell-model and IBM-4 calculations demonstrates good agreement between theory and experiment, with the majority of predicted low-lying, low-spin T = 0 states now identified. There is a dramatic change in the level density at low excitation energies for the N = Z nucleus Ga-62 when compared with neighbouring odd-odd Ga isotopes where, in contrast, the low-lying level structure is dominated by configurations with T = 1 pairing interactions between excess neutrons. This illustrates the distinctively different aspects of nuclear structure exhibited by nuclei with N = Z.
- N = Z