Paschos-Wolfenstein Relationship for Nuclei and the NuTeV sin^2(theta_W) Measurement

We discuss nuclear effects in the Paschos-Wolfenstein relationship in the context of extraction of the weak mixing angle. We point out that the neutron excess correction to the Paschos-Wolfenstein relationship for a neutron-rich target is negative and large on the scale of experimental errors of a recent NuTeV measurement. We found a larger neutron excess correction to the Paschos-Wolfenstein relationship for total cross sections than that discussed by the NuTeV collaboration. Phenomenological applications of this observation are discussed in the context of the NuTeV deviation. Uncertainties in the neutron excess correction are estimated. Effects due to Fermi motion, nuclear binding, and nuclear shadowing are also discussed in the context of total cross sections.