  In semi-leptonic and other weak decays of mesons, the hadronic matrix
elements of the operators in the weak Hamiltonian are parametrized by standard
sets of independent, Lorentz invariant, form factors. For the case of
pseudoscalar to vector meson transitions, it has been shown that a Quark Model
description leads to relations between some of the form factors. Here, I give
an alternate, and more general, proof of those relations and thus confirm that,
in the Quark Model, not all the form factors for pseudoscalar to vector meson
transitions are independent. As an application of this result, a Quark Model
measurement of the CKM parameter |Vub| can be obtained, where the dependence on
all hadronic form factors is eliminated.
