Tests of the Peripheral Model for a Cluster Knockout Reaction

Abstract

The reaction ${}_{}{}^6{}_{}{}^{}\mathrm{Li}(\alpha ,2\mathrm{}\alpha )d$ was studied at 50.4, 59.0, 60.5, 70.3 and 79.6 MeV. The angular distributions and energy dependence of the off-energy-shell $\alpha -\alpha$ cross section were extracted and compared with those for free $\alpha -\alpha$ scattering. The agreement between the two is excellent, as predicted by the peripheral model in the quasifree approximation, but the quasifree approximation is not precise enough.