Abstract
Previously observed positive and negative parity states of I-127 have been interpreted using a particle-rotor model. Experimental energies and transition properties have been compared to those predicted by the calculation. The results show that this simple model with very few parameters can successfully explain most of the structure of I-127 at low and medium energies. I-127 being only three protons beyond the closed Z = 50 shell with N = 74 relatively far from the middle of the 50-82 neutron region (N = 66), there is evidence that it is slightly deformed. The rotational structure of the Delta J = 1 band built on an unusually low-lying g(9/2) proton-hole state (9/2(+)[404]) has been naturally very well predicted as well as other rotational features for the g(7/2), d(5/2) and h(11/2) orbitals. Complete particle-core multiplets have been successfully identified for the first time.