ARE QUARKS AND LEPTONS RELATED BY C, P AND T SYMMETRIES?
R. Foot, Henry R. Lew, Raymond R. Volkas · Modern Physics Letters A · 1993
It is possible that the similarities between the quarks and leptons arise from the spontaneous breaking of an exact quark-lepton Z2 discrete symmetry. We study the connection between this type of discrete symmetry and the discrete symmetries of charge conjugation, parity and time reversal: C, P and T.