Octupole signatures in 124,125Ba

Matière Nucléaire; International audience; The gamma decay of the nuclei 124,125Ba has been investigated with the EUROBALL array, using the reaction 64Ni+64 Ni at E_{beam} = 255 and 261 MeV. Six new E1 transitions have been found in the nucleus 125Ba, suggesting a significant role of octupole correlations in the origin of its parity doublets. The pi = 3-level of the nucleus 124Ba has been identified for the first time. Its excitation energy is in very good agreement with a prediction based on a microscopic model including octupole interactions.