Spectroscopy near the proton drip-line in the A=130 mass region

Abstract

The near proton drip-line nucleus 126Pr was studied via in-beam γ-ray spectroscopy using the 40Ca+82Mo 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 πh11/2 ⋇ νh11/2 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 126Pr and 128Pr get smaller than in the heavier Pr isotopes, suggesting a sudden change in deformation close to the proton drip line.