Evidence for the Jacobi shape transition in hot 46Ti

The gamma-rays from the decay of the GDR in the compound nucleus reaction O-18+Si-28 at bombarding enery of 105 MeV have been measured in an experiment using a setup consisting of the combined EUROBALL IV, HECTOR and EUCLIDES arrays. The shape of the rotating compound nucleus, Ti-46, is expected to undergo the Jacobi transition around spin 28 h. A comparison of the GDR lineshape data with the predictions of the thermal shape fluctuation model, based on the most recent rotating liquid drop LSD calculations, shows evidence for such Jacobi shape transition. In addition to the previously found broad structure in the CDR lineshape region at 18-25 MeV caused by large deformations, the presence of a low energy component (around 10 MeV), due to the Coriolis splitting in prolate, well deformed shape has been identified for the first time.