Study of the giant resonance in O 16 by inelastic electron scattering

Abstract

The spectra of electrons inelastically scattered by oxygen nuclei show a series of prominent peaks which are assumed to correspond to the excitation of discrete levels. By varying the incident electron energy and the scattering angle the dependence of the inelastic form factor on momentum transfer is studied. Use of the Born approximation for the scattering cross section then enables us to determine the multipolarity and parity change of the transitions. Results and analysis are presented of E1 transitions to excited states at 22.6 and 25.7 MeV, and of an E2 transition to an excited state at 24.1 MeV. The E1 transitions are probably those responsible for the giant resonance observed in the photoproduction of neutrons and protons from oxygen. Details are given of our calculations of radiative tails and radiative corrections to the data.