Measurement of Muon-Neutrino and -Antineutrino Scattering off Electrons

Abstract

Muon-neutrino and -antineutrino scattering off electrons was detected in a 19-ton Al spark chamber, exposed to the wide-band $\nu$ ($\overline{\nu }$) beam from the CERN proton synchrotron. The background was determined experimentally. 11 (10) genuine ${\nu }_{{\mu }^{-}}$ (${\overline{\nu }}_{{\mu }^{-}}$) $e$ scattering events were found. The respective cross sections are $(1.1\mathrm{}\pm 0.6)\times {10}^{-42\mathrm{}}(E_{\nu }/\mathrm{GeV})$ ${\mathrm{cm}}^2$ and $(2.2\mathrm{}\pm 1.0)\times {10}^{-42\mathrm{}}(E_{\nu }/\mathrm{GeV})$ ${\mathrm{cm}}^2$. The analysis excludes a pure $V-A$ interaction, and makes a pure $V$ or $A$ theory improbable. The data agree well with the Salam-Weinberg model and ${{sin}^2\theta }_{\mathrm{W}}=0.35\mathrm{}\pm 0.08$.