MEASUREMENT OF THE NEUTRAL TO CHARGED CURRENT CROSS-SECTION RATIOS IN NEUTRINO AND ANTINEUTRINO NUCLEON-INTERACTIONS AND DETERMINATION OF THE WEINBERG ANGLE

The cross section ratios of neutral and charged current interactions induced by neutrinos and antineutrinos in iron have been measured in the 200 GeV narrow-band beam at the CERN SPS. We findR v =0.301±0.007 andR v =0.363±0.015 for a hadron energy cut of 10 GeV. The results are in agreement with the standard model of electroweak interactions. In the\(\overline {MS} \) renormalization scheme at the scale of theW boson mass\(\sin ^2 \hat \theta _W \left( {m_W } \right) = 0.226 \pm 0.012\) is obtained, where the error represents the experimental uncertainty. The theoretical uncertainty is estimated to beΔsin2θ W =±0.006.