Radiative fusion from very symmetric reactions: the giant dipole resonance in the 179Au nucleus

The spectra of high-energy γ rays emitted by the Giant Dipole Resonance (GDR) built on moderately excited states associated with the evaporation of 0, 1 and 2 nucleons were measured in the 90 Zr + 89 Y symmetric fusion reaction. The radiative fusion data suggest statistical emission from the compound nucleus. In addition, the analysis of the high-energy γ -ray spectra associated with the different evaporation channels at the present temperature of 0.7 MeV and spin range 15–20 ¯ h show a fairly narrow width of 5.0 ± 0.35 MeV. This value is smaller than what would be expected in a nucleus where shell effects do not play a role.  2003 Published by Elsevier Science B.V.