A consistent treatment of intrinsic and collective coordinates is applied to
the calculation of matrix elements describing nuclear double beta decay
transitions. The method, which was developed for the case of nuclear rotations,
is adapted to include isospin and number of particles degrees of freedom. It is
shown that the uncertainties found in most models, in dealing with these decay
modes, are largely due to the mixing of physical and spurious effects in the
treatment of isospin dependent interactions.Comment: 4 pages, 2 figures, RevTe