A Precise Measurement of the Weak Mixing Angle in Neutrino-Nucleon Scattering

Abstract

We report a precise measurement of the weak mixing angle from the ratio of neutral current to charged current inclusive cross-sections in deep-inelastic neutrino-nucleon scattering. The data were gathered at the CCFR neutrino detector in the Fermilab quadrupole-triplet neutrino beam, with neutrino energies up to 600 GeV. Using the on-shell definition, ${\rm sin ^2\theta_W} \equiv 1 - \frac{{\rm M_W} ^2}{{\rm M_Z} ^2}$, we obtain ${\rm sin ^2\theta_W} = 0.2218 \pm 0.0025 ({\rm stat.}) \pm 0.0036 ({\rm exp.\: syst.}) \pm 0.0040 ({\rm model})$.