Tests for Neutral Currents in Neutrino Reactions

Abstract

Neutral currents predicted by weak-interaction models of the type discussed by Weinberg may be detected in neutrino reactions. Limits on the ratio $R$ of $\ensuremath{\sigma}(\ensuremath{\nu}+N\ensuremath{\rightarrow}\ensuremath{\nu}+X)$ to $\ensuremath{\sigma}(\ensuremath{\nu}+N\ensuremath{\rightarrow}{\ensuremath{\mu}}^{\ensuremath{-}}+X)$ are obtained independent of any dynamical assumption. For the total cross section for high-energy neutrinos, we find $R\ensuremath{\ge}0.18$, provided the Weinberg mixing angle satisfies ${{sin}^{2}\ensuremath{\theta}}_{W}\ensuremath{\le}0.33$. For the production of a single ${\ensuremath{\pi}}^{0}$ we find ${R}^{\ensuremath{'}}\ensuremath{\ge}0.50$ contrasted with the experimental result ${R}^{\ensuremath{'}}\ensuremath{\le}0.14$ using only the assumption of (3,3)-resonance dominance. Applications are also given to antineutrino reactions.