Standard model explanations for the NuTeV electroweak measurements

摘要

The NuTeV Collaboration has measured the electroweak parameters sin(2) theta(W) and rho in neutrino-nucleon deep-inelastic scattering using a sign-selected beam. The nearly pure nu or nu beams that result provide many of the cancellations of systematics associated with the Paschos-Wolfenstein relation. The extracted result for sin(2) theta(W) (on-shell) = 1 - M-W(2)/M-Z(2) is three standard deviations from prediction. We discuss standard model explanations for the puzzle. [References: 15]