Spectroscopy near the proton drip-line in the A=130 mass region (original) (raw)

The near' proton drip-line nucleus 12epr was studied via in-beam v-ray spectroscopy using the 4~ reaction at 190 MeV. We observed for the first time excited states above the known isomer in this nucleus, up to spin 31h. The observed band is assigned to a 7rh11/2 @ vhH/2 configuration. The experimental information suggest a spin 8 + for the lowest observed state. With such a spin assignment the excitation energy of the excited states in 12epr and ~2SPr get smaller than in the heavier Pr isotopes, suggesting a sudden change in deformation close to the proton drip line.