Studies on the Weak Charges of Particles
  In order to include massive neutrino theoretically, a new concept of the weak charges of the particles, fundamental fermions, intermediate bosons and hadrons, is introduced. A new conservation law of the weak charge is first reported. According to the chirality of the weak charge the origin of parity nonconservation in the weak interactions is reasonably explained. According to the symmetry of the weak charge, an extension of the standard model is proposed. In this scenario, all the three generations of neutrinos are massive Dirac particles; both the right-handed neutrinos and the right-handed neutral baryons have zero weak charge, and so they do not take part in the weak interactions. 
Zhi-qiang Shi