In order to search for a rare kind of shape phase transition in hot rotating nuclei, measurements have been performed of high energy gamma rays from the ¹⁸⁸Os nucleus at high excitation energy and high spin. In addition, the possibility of observing the Giant Quadrupole Resonance (GQR) built on excited states has been explored. To carry out more detailed measurements, a sum-spin spectrometer was set up in complete 4\pi configuration. Preliminary results on Giant Dipole Resonance (GDR) decay from hot rotating ¹⁹²Pt nucleus, obtained with the help of this new device, are presented.

PACS numbers: 24.30.Cz, 24.60.Dr, 24.60.–k, 27.70.+q