Second class current and anomalies in neutrino reactions

The problem of second class current is investigated through the (anti-)neutrino reactions. In the neutrino quasi-elastic scattering, it is shown that the magnitude of a second class current comparable to the weak magnetism in the nucleon level is compatible with the recent experimental data. Furthermore the anomalous behaviour in deep inelastic (anti-)neutrino reactions are discussed by introducing a second class current in the quark level with a charged weak boson of finite mass. It is shown that y distribution of the differential cross section is the most direct manifestation of the effect of the second class current in the quark level. (auth.)