Electromagnetic decay of the giant quadrupole resonances

A study is made of the electromagnetic decay of the 208Pb giant quadrupole resonance excited by inelastic scattering of 17O at 380 MeV. Due to the instability of the giant quadrupole resonance with respect to compound-nucleus formation and to neutron emission, the time over which the radiation is produced is not much greater than the time in which the direct reaction occurs. Angular distributions of the γ-rays produced in transitions to several low-lying states of the residual nucleus are calculated and their dependence on effects due to the proximity of the interacting nuclei is discussed.