Upper bound for the induced pseudoscalar form factor in muon capture

It is shown, on very general grounds, that the Goldberger-Treiman (GT) value for the induced pseudoscalar form factor, h/sub A/, in muon-capture reactions represents an upper bound for any realistic h/sub A/ that takes into account corrections to (i) nuclear GT relations and (ii) the hypothesis of partial conservation of axial-vector current. The proof is independent of the particular model one might choose for these corrections. An application of this bound to muon capture on 12C makes it difficult to understand the sign of the experimentally reported induced pseudotensor form factor in 12B β decay