  We determine all Lie groups compatible with the gauge structure of the
Standard Elementary Particle Model (SM) and their representations. The groups
are specified by congruence equations of quantum numbers. By comparison with
the experimental results, we single out one Lie group and show that this choice
implies certain old and new correlations between the quantum numbers of the SM
quantum fields as well as some hitherto unknown group theoretical properties of
the Higgs mechanism.
