Evidence for exchange effects in inelastic scattering processes from angular correlation data

Abstract

It is shown that the behaviour of the angular correlation function symmetry angle φ 0 at backward scattering angles can be taken as evidence for exchange effects in inelastic scattering processes. The observed behaviour of φ 0 for θ > 140° in data from 12C( α, α′ γ 4.43) and 28Si( α, α′ γ 1.77) at a bombarding energy of 22.5 MeV is similar to that which has been observed for the exchange mode in mass-transfer reactions. That the corresponding α′ angular distribution data can be well represented by a PWBA exchange mode theory in this region supports this conclusion.