A High Statistics Search for Electron-Neutrino --> Tau-Neutrino Oscillations

We present new limits on nu_e to nu_tau and nu_e to nu_sterile oscillations by searching for electron neutrino dissappearance in the high-energy wide-band CCFR neutrino beam. Sensitivity to nu_tau appearance comes from tau decay modes in which a large fraction of the energy deposited is electromagnetic. The beam is composed primarily of muon neutrinos but this analysis uses the 2.3% electron neutrino component of the beam. Electron neutrino energies range from 30 to 600 GeV and flight lengths vary from 0.9 to 1.4 km. This limit improves the sensitivity of existing limits and obtains a lowest 90% confidence upper limit in sin**2(2*alpha) of 9.9 x 10**(-2) at delta-m**2 of 125 eV**2.Comment: submitted to Phys. Rev. D. Rapid Com

A Search for Muon-neutrino to Electron-neutrino and Muon-antineutrino to Electron-antineutrino Oscillations at NuTeV

Limits on $\nu_\mu \to \nu_e$ and $\bar\nu_\mu \to \bar\nu_e$ oscillations are extracted using the NuTeV detector with sign-selected $\nu_\mu$ and \nub_\mu beams. In \nub_\mu mode, for the case of $\sin^2 2\alpha = 1$, $\Delta m^2 > 2.6$ ${\rm eV^2}$ is excluded, and for $\Delta m^2 \gg 1000$ ${\rm eV^2}$, $\sin^2 2\alpha > 1.1 \times 10^{-3}$. The NuTeV data exclude the high $\Delta m^2$ end of $\bar\nu_\mu \to \bar\nu_e$ oscillations parameters favored by the LSND experiment without the need to assume that the oscillation parameters for $\nu$ and \nub are the same. We present the most stringent experimental limits for $\nu_\mu (\bar{\nu}_\mu) \to \nu_e (\bar{\nu}_e)$ oscillations in the large $\Delta m^2$ region.Comment: 4 pages, 3 figures. Submitted to Phys. Rev. Letters, UR-164

Observation of an Anomalous Number of Dimuon Events in a High Energy Neutrino Beam

A search for long-lived neutral particles (N^0's) with masses above 2.2 GeV/c^2 that decay into at least one muon has been performed using an instrumented decay channel at the NuTeV experiment at Fermilab. Data were examined for particles decaying into the final states mu mu, mu e, and mu pi. Three mu mu events were observed over an expected Standard Model background of 0.069 +/- 0.010 events; no events were observed in the other modes.Comment: 5 pages, 3 figures, Submitted to Phys. Rev. Let

Nuclear Structure Functions in the Large x Large Q^2 Kinematic Region in Neutrino Deep Inelastic Scattering

Data from the CCFR E770 Neutrino Deep Inelastic Scattering (DIS) experiment at Fermilab contain events with large Bjorken x (x>0.7) and high momentum transfer (Q^2>50 (GeV/c)^2). A comparison of the data with a model based on no nuclear effects at large x, shows a significant excess of events in the data. Addition of Fermi gas motion of the nucleons in the nucleus to the model does not explain the excess. Adding a higher momentum tail due to the formation of ``quasi-deuterons'' makes some improvement. An exponentially falling F_2 \propto e^-s(x-x_0) at large x, predicted by ``multi-quark clusters'' and ``few-nucleon correlations'', can describe the data. A value of s=8.3 \pm 0.7(stat.)\pm 0.7(sys.) yields the best agreement with the data.Comment: 4 pages, 4 figures, 1 table. Sibmitted to PR

A measurement of alphas(Q2)alpha_s(Q^2) from the Gross-Llewellyn Smith Sum Rule

We extract a set of values for the Gross-Llewellyn Smith sum rule at different values of 4-momentum transfer squared ($Q^{2}$), by combining revised CCFR neutrino data with data from other neutrino deep-inelastic scattering experiments for $1 < Q^2 < 15 GeV^2/c^2$. A comparison with the order $\alpha^{3}_{s}$ theoretical predictions yields a determination of $\alpha_{s}$ at the scale of the Z-boson mass of $0.114 \pm^{.009}_{.012}$. This measurement provides a new and useful test of perturbative QCD at low $Q^2$, because of the low uncertainties in the higher order calculations.Comment: 4 pages, 4 figure

Search for the Lepton Number Violating Process nu_mu-bar e^- -> mu^- nu_e-bar

The NuTeV experiment at Fermilab has used a sign-selected neutrino beam to perform a search for the lepton number violating process nu_mu-bar e^- -> mu^- nu_e-bar, and to measure the cross-section of the Standard Model inverse muon decay process nu_mu e^- -> mu^- nu_e. NuTeV measures the inverse muon decay asymptotic cross-section sigma/E to be 13.8 +/- 1.2 +/- 1.4 x 10^-42 cm^2/GeV. The experiment also observes no evidence for lepton number violation and places one of the most restrictive limits on the LNV/IMD cross-section ratio at < 1.7% at 90% C.L. for V-A couplings and < 0.6% for scalar couplings.Comment: 4 pages, 4 figures, 2 tables. Submitted to Physics Review Letter