$sup 6$Li($alpha$,2$alpha$)$sup 2$H reaction at 700 MeV and the $alpha$-d momentum distribution

The results of an experimental study of the reaction $sup 6$Li($alpha$,2$alpha$)$sup 2$H at 700 MeV are given. A comparison with the data from seven other reactions pertaining to the $alpha$$sup +$d cluster structure of $sup 6$Li is presented. The amplitude for the virtual transition $sup 6$Li $Yields$ $alpha$ + d obtained in three of these experiments and the present one are comparable. The internal momentum distributions extracted with the plane- wave impulse approximation in four of the experiments are compatible with a pole form, the width parameter being given by the $alpha$-separation energy in $sup 6$Li. The remarkable consistency among these results is seen as evidence for the validity of the simple models used for both the reaction mechanism (PWIA) and the $alpha$--d vertex (pole approximation) in $sup 6$Li. (NL)