Excitation-energy dependence of the giant dipole resonance width

Abstract
High-energy γ rays have been measured in coincidence with heavy fragents in deeply inelastic reactions of Xe136 +48Ti at 18.5 MeV/nucleon. The giant dipole resonance (GDR) strength function is deduced from an analysis of the photon spectra within the statistical model. The GDR width Γ is studied as a function of the fragment excitation energy E*. A saturation at about Γ=10 MeV is observed for E*/A≥1.0 MeV/nucleon.