Shape evolution of the hot giant dipole resonance

A systematic description of the evolution of the giant dipole resonance (GDR) at non-zero temperature T is given within the framework of two versions PDM-1 and PDM-2 of the Phonon Damping Model (PDM). The PDM interprets the damping of the GDR as a result of coupling to all ph, pp and hh configurations at T not equal 0, where the coupling to pp and hh configurations is decisively important for an adequate description of the increase and saturation of the GDR width as a function of T. The numerical calculations have been performed for the GDR width, the strength function and the integrated yield of the gamma rays in Sn-120 and Pb-208 at 0 less than or equal to T less than or equal to 6 MeV. The results obtained are found in a reasonable agreement with the most recent experimental data for all these three characteristics including the saturation of the yields within the GDR region and in the region above it. Predictions have been made for the GDR shape in both nuclei at T up to 6 MeV and for the integrated yield of gamma rays in Pb-208. (C) 1999 Elsevier Science B.V.