Searches for Neutrino Oscillations  Neutrino physics at accelerators  Neutrino physics at accelerators

Standard physics experiments

Two experiments are presently running at the Fermilab 800 GeV Tevatron. NuTeV uses a neutrino beam from the decay of sign-selected hadrons, which allows to unambiguously distinguish $\nu$ and $\overline{\nu}$ interactions. With such a beam, the measurement of the cross-section ratio between neutral-current and charged-current neutrino-nucleon interactions leads to a precise determination of the weak mixing angle, sin $^{2}\theta_{W}$, and also to a precise measurement of the parameter $\rho$ which describes the ratio of neutral to charged-current coupling strengths. NuTeV will measure sin $^{2}\theta_{W}$ with an expected total error of $\pm 0.0025$ and $\rho$ with an error of $\pm 0.010$. Within the electroweak theory these measurements can be expressed in terms of equivalent measurements of the top quark and W boson masses. Any significant difference between the NuTeV results and direct measurements of the top and W masses would provide indirect evidence for new physics. Experiment E-872 (DONUT, for Direct observation of NU-Tau) aims at the first observation of $\nu_\tau$ charged-current interactions. D_S mesons produced by the interactions of 800 GeV protons in a beam dump decay to $\nu_\tau$'s which are detected by observing $\tau$ production and subsequent decay in an emulsion target.