Cross-section ratio sigma(. nu. n)/sigma(. nu. p) for charged-current and neutral-current interactions below 10 GeV

We have measured the cross-section ratio $\frac{\ensuremath{\sigma}(\ensuremath{\nu}n)}{\ensuremath{\sigma}(\ensuremath{\nu}p)}$ for both charged-current and neutral-current interactions at low energy. The experiment used the wide-band neutrino beam at Brookhaven National Laboratory. The detector was the 7-foot bubble chamber filled with a 62% neon-hydrogen mixture. For charged-current events we find that the ratio reaches an asymptotic value of 1.80\ifmmode\pm\else\textpm\fi{}0.19 for neutrino energies above 1 GeV. For neutral-current events we measure the ratio to be 1.07\ifmmode\pm\else\textpm\fi{}0.24. Both of these results are in agreement with the quark model.