A new symmetric three-body coupling model has been developed for the description of the final state of knockout reactions. This model provides an exact description of the three-body final state when either one or both of the two distorting optical potentials vanish. Such a model gives a good description of the situation present in the knockout reactions in the extreme peripheral region, where at least one of the distorting optical potentials is ineffective. Comparison between the predictions of this model and the conventional kinematic coupling model for the 140 MeV ${}_{}{}^2{}_{}{}^{}\mathrm{H}$(α,α’p)n reaction and the 90 MeV ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$(α,2α${)}^{12}$C reaction are illustrative of the conclusions which could be drawn from cluster knockout reaction analyses.

• Received 22 January 1991

DOI:https://doi.org/10.1103/PhysRevC.45.2387