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

Abstract

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