THE JACOBI TRANSITION AND THE GIANT-DIPOLE RESONANCE IN RAPIDLY ROTATING HOT NUCLEI

The giant-dipole resonance (GDR) in rapidly rotating hot nuclei is cal culated at constant spin by projection from the GDR response function at constant angular velocity. The theory is applied to the Jacobi phas e transition of a hot rotating liquid drop and the GDR is found to be a sensitive signature of the transition. Comparison with recent experi ments on Sc-45 confirm a Jacobi phase transition from oblate to almost prolate shapes with large deformation.