Test of flavor-changing neutral currents from elastic neutrino- and antineutrino-proton scattering

The general form of the neutral currents satisfying "natural" conservation of strangeness is considered for the general class of SU(2) × U(1) gauge models and is tested against the existing data on elastic $\nu p$ and $\overline{\nu }p$ scattering. The existence of charm-changing neutral currents seems to be a possibility. In addition, we predict the ratio of the charged-current $\nu$ and $\overline{\nu }$ cross sections $R_{\mathrm{CC}}=\frac{{\sigma }_{\nu }}{{\sigma }_{\nu }}$ to be less than about 0.8 at high energies.