A New Approach to the Family Structure

Abstract

In this letter, we introduce a new approach to formulate the family structure of the standard model. Trying to mimic the highly contrained representation structure of the standard model while extending the symmetry, we propose a $SU(4)\otimes SU(3)\otimes SU(2)\otimes U(1)$ symmetry with a SM-like chiral spectra basically "derived" from the gauge anomaly constraints. Embedding the SM leads to $SU(4)_A\otimes SU(3)_C\otimes SU(2)_L\otimes U(1)_X$ models, which upon the $SU(4)_A\otimes U(1)_X \longrightarrow U(1)_Y$ symmetry breaking, gives the three families naturally as a result. A specific model obtained from the approach is illustrated. The model, or others from our approach, holds promise of a very interesting phenomenology. We sketch some of the results here. An interesting possiblity of supersymmetrizing the model with the EW-Higgses already in the spectrum is noted. A comparison with other approaches is also discussed.