Formula omitted] reaction in the giant resonance region

Abstract

The energy spectra of α-particles and the (e, α) cross section for 24Mg were measured with electrons in the energy region from 14 to 30 MeV to investigate α-particle emission from the giant resonance. The ( γ, α 0) and ( γ, α) cross sections for 24Mg were deduced from energy spectra and the (e, α) cross section using the virtual photon technique. E1 and E2 components were obtained from the analysis of angular distributions. A peak of 20 MeV seen in the (γ, n), (γ, p) and absorption cross sections is not observed in the (γ, α) cross section. The cross sections are explained by the statistical model with isospin mixing in the measured energy region, except around 20 MeV.