First evidence of an octupole rotational band in Ge isotopes

The spectroscopy of Ge-71 has been investigated via the fusion-evaporation reaction Ge-74(alpha, alpha 3n)Ge-71. Collective structures including a rotational band built on the 15/2(-) octupole state in Ge-71 have been established. The observation of strong E1 transitions and the well-behaved rotational sequence built on the 15/2(-) octupole state provide the first experimental evidence of an octupole rotational band in Ge isotopes, suggesting an enhanced octupole correlation around N = 40 in the A approximate to 70 region. A newly developed semimicroscopic cluster model provides a good description of the octupole characteristics of Ge-71.

Automated summary

The spectroscopy of Ge-71 was investigated and the first experimental evidence of an octupole rotational band in Ge isotopes was found, suggesting enhanced octupole correlation around N = 40 in the A approximate to 70 region.