  In standard potential-model descriptions of the Be7(p,gamma)B8 reaction the
Be7+p spectroscopic factors S appear in the cross section. We argue that the
microscopic substructure effects which are represented by S are short-ranged
and cannot affect the asymptotic normalization of the wave function. We believe
that the standard way of describing reactions in a potential model may be
incorrect and the low-energy cross section should not depend on S in the case
of external capture reactions, like Be7(p,gamma)B8
