Abstract
A theory of electromagnetic and weak interactions based on the O(4) gauge group is formulated along the general program put forward recently by Pais. In our scheme the hadron symmetry SU(3) × SU(3)′ is incorporated in such a way that the model has a (kinematical) ΔI=12 rule for nonleptonic weak decays. The lepton assignment may be made to produce CP-violation effects which are more "convergent" without enlarging the gauge group. There is no lower bound to the masses of the intermediate vector bosons, while the upper limit for one of the charged W's is only 18 GeV. The elastic reaction cross sections σ(νee) and σ(ν¯ee) are about 1.4 times the usual VA values. Other physical features of this model are also discussed in some detail.