On Symmetry of Elementary Particles

The new quantum number \sigma is introduced. It is shown that the conservation of \sigma-number results in the conservation of difference between baryon and lepton numbers obtained earlier by Georgi and Glashow. The conservation of \sigma -number also predicts that electron type neutrino mass is exactly zero. The quark-lepton symmetry is discussed. It is shown that the nature of quark-lepton symmetry is reflected by the fact that elementary particles of the same generation are subject to the symmetry transformation represented by 4-group of diedr. It is also shown that colorless elementary particles are subject to the same symmetry transformation. The new elementary particles (transbaryons) are predicted.