  It is shown that a chiral SU(2) model can break Lorentz symmetry
spontaneously at the Lagrangian level when gauge bosons become massive. This
model seems to propose the principles and conceptual foundations leading to a
unified picture of fermions, and may reduce the standard theory to a far
simpler form. The model suggests describing leptons and quarks as
quasi-excitations, while electromagnetic and strong interactions as secondary
interactions mediated by Nambu-Goldstone bosons originating from spontaneous
violations of global SU(2) and rotational symmetries. Both the possibility of
observing Lorentz-violating phenomena and their magnitudes are discussed. The
model also provides an alternative scenario for baryon and lepton asymmetries
of the Universe.
