Determination of electroweak parameters from the elastic scattering of muon neutrinos and antineutrinos on electrons

Total and differential cross sections for ${\nu }_{\mu }e\to {\nu }_{\mu }e$ and ${\overline{\nu }}_{\mu }e\to {\overline{\nu }}_{\mu }e$ are measured. Values for the model-independent neutral-current couplings of the electron are found to be $g_V=-0.107\mathrm{}\pm 0.035\left(\mathrm{stat}\right)\pm 0.028\left(\mathrm{syst}\right)$ and $g_A=-0.514\mathrm{}\pm 0.023\left(\mathrm{stat}\right)\pm 0.028\left(\mathrm{syst}\right)$. The electroweak mixing parameter ${sin}^2{\theta }_W$ is determined to be 0.195±0.018(stat)±0.013(syst). Limits are set for the charge radius and magnetic moment of the neutrino as $\left(〈r^2〉\right)<\mathrm{}0.24\mathrm{}\times {10}^{-32\mathrm{}}$ ${\mathrm{cm}}^2$ and $f_{\mu }<0.85\mathrm{}\times {10}^{-9\mathrm{}}$ Bohr magnetons, respectively.