General expressions for ${sin}^2{\theta }_W$, $R\equiv \frac{{\sigma }_{\mathrm{nc}}^{\nu N}}{{\sigma }_{\mathrm{cc}}^{\nu N}}$, and $\overline{R}\equiv \frac{{\sigma }_{\mathrm{nc}}^{\overline{\nu }N}}{{\sigma }_{\mathrm{cc}}^{\overline{\nu }N}}$ are given in the quarkparton model with the charmed quark. Convenient parametrizations of the experimental results for the charged and neutral $(\nu ,\overline{\nu })N$ interactions, in the scaling limit, are introduced and their implications for ${\theta }_W$ are discussed. In particular, we study the effect of the charmed quark in the neutral current processes explicitly by analyzing the available experimental data. Constraints on the relative contributions of the antiquarks, strange quarks, and charmed quarks are obtained.

• Received 18 March 1975

DOI:https://doi.org/10.1103/PhysRevD.11.3305